Xamarin Visual Studio Error MSB4064 and MSB4063 -

i've been trying several days trying xamarin , visual studio 2015 work. have error create new blank xamarin project. project generated errors:

warning ide0006 error encountered while loading project. project features, such full solution analysis failed project , projects depend on it, have been disabled.   droid2      1   active warning     "checksumalgorithm" parameter not supported "csc" task. verify parameter exists on task, , settable public instance property.   droid2           warning     "csc" task not initialized input parameters.  droid2   

i've tried several times uninstalling xamarin , reinstalling no avail.

the build log file big add in toto added last bit. (30000 char limit)

    target "_extractlibraryprojectimports" in file "c:\program files (x86)\msbuild\xamarin\android\xamarin.android.common.targets":       using "readlibraryprojectimportscache" task assembly "c:\program files (x86)\msbuild\xamarin\android\xamarin.android.build.tasks.dll".       task "readlibraryprojectimportscache"         task readlibraryprojectimportscache           cachefile: obj\debug\libraryprojectimports.cache           jars:            resolvedassetdirectories:            resolvedresourcedirectories:            resolvedenvironmentfiles:            resolvedresourcedirectorystamps:        done executing task "readlibraryprojectimportscache".     done building target "_extractlibraryprojectimports" in project "droid2.csproj".     target "_crunchlibraryprojectimports" skipped, due false condition; ( '$(androidexplicitcrunch)' == 'true' , '$(androidapplication)' != '' , $(androidapplication)) evaluated ( 'false' == 'true' , 'true' != '' , true).     target "_addmultidexdependencyjars" in file "c:\program files (x86)\msbuild\xamarin\android\xamarin.android.common.targets":       task "createitem" skipped, due false condition; ('$(androidenablemultidex)' == 'true') evaluated ('false' == 'true').     done building target "_addmultidexdependencyjars" in project "droid2.csproj".     target "_buildlibraryimportscache" in file "c:\program files (x86)\msbuild\xamarin\android\xamarin.android.common.targets":       skipping target "_buildlibraryimportscache" because output files up-to-date respect input files.       input files: c:\program files (x86)\reference assemblies\microsoft\framework\monoandroid\v1.0\java.interop.dll;c:\program files (x86)\reference assemblies\microsoft\framework\monoandroid\v6.0\mono.android.dll;c:\program files (x86)\reference assemblies\microsoft\framework\monoandroid\v1.0\mscorlib.dll;c:\program files (x86)\reference assemblies\microsoft\framework\monoandroid\v1.0\system.core.dll;c:\program files (x86)\reference assemblies\microsoft\framework\monoandroid\v1.0\system.dll;c:\program files (x86)\reference assemblies\microsoft\framework\monoandroid\v1.0\facades\system.runtime.dll;c:\program files (x86)\reference assemblies\microsoft\framework\monoandroid\v1.0\system.xml.dll;c:\program files (x86)\reference assemblies\microsoft\framework\monoandroid\v1.0\system.xml.linq.dll;d:\play app\droid2\droid2\droid2.csproj;obj\debug\build.props       output files: obj\debug\libraryimports.cache     done building target "_buildlibraryimportscache" in project "droid2.csproj".     target "_getlibraryimports" in file "c:\program files (x86)\msbuild\xamarin\android\xamarin.android.common.targets":       using "readimportedlibrariescache" task assembly "c:\program files (x86)\msbuild\xamarin\android\xamarin.android.build.tasks.dll".       task "readimportedlibrariescache"         task readimportedlibrariescache           cachefile: obj\debug\libraryimports.cache           nativelibraries:            jars:            manifestdocuments:        done executing task "readimportedlibrariescache".       task "createitem" skipped, due false condition; ('@(extractednativelibraryimports)' != '') evaluated ('' != '').     done building target "_getlibraryimports" in project "droid2.csproj".     target "getnativeprojectlibraries" skipped, due false condition; ($(nativeandroidinstalled)) evaluated (false).     target "_getlibraryimports" skipped. built successfully.     target "_checkduplicatejavalibraries" in file "c:\program files (x86)\msbuild\xamarin\android\xamarin.android.common.targets":       using "checkduplicatejavalibraries" task assembly "c:\program files (x86)\msbuild\xamarin\android\xamarin.android.build.tasks.dll".       task "checkduplicatejavalibraries"           javasourcefiles:           javalibraries:           libraryprojectjars:       done executing task "checkduplicatejavalibraries".     done building target "_checkduplicatejavalibraries" in project "droid2.csproj".     target "_validateresourcecache" in file "c:\program files (x86)\msbuild\xamarin\android\xamarin.android.common.targets":       using "readadditionalresourcesfromassemblycache" task assembly "c:\program files (x86)\msbuild\xamarin\android\xamarin.android.build.tasks.dll".       task "readadditionalresourcesfromassemblycache"         task readadditionalresourcesfromassemblycache           cachefile: obj\debug\resourcepaths.cache           additionalandroidresourcepaths:            additionaljavalibraryreferences:            additionalnativelibraryreferences:            isvalid: true       done executing task "readadditionalresourcesfromassemblycache".       task "delete" skipped, due false condition; ( '$(_isresourcecachevalid)' == 'false' ) evaluated ( 'true' == 'false' ).     done building target "_validateresourcecache" in project "droid2.csproj".     target "_setupdesigntimebuildforintellisense" in file "c:\program files (x86)\msbuild\xamarin\android\xamarin.android.common.targets":     done building target "_setupdesigntimebuildforintellisense" in project "droid2.csproj".     target "_buildadditionalresourcescache" in file "c:\program files (x86)\msbuild\xamarin\android\xamarin.android.common.targets":       skipping target "_buildadditionalresourcescache" because output files up-to-date respect input files.       input files: c:\program files (x86)\reference assemblies\microsoft\framework\monoandroid\v1.0\java.interop.dll;c:\program files (x86)\reference assemblies\microsoft\framework\monoandroid\v6.0\mono.android.dll;c:\program files (x86)\reference assemblies\microsoft\framework\monoandroid\v1.0\mscorlib.dll;c:\program files (x86)\reference assemblies\microsoft\framework\monoandroid\v1.0\system.core.dll;c:\program files (x86)\reference assemblies\microsoft\framework\monoandroid\v1.0\system.dll;c:\program files (x86)\reference assemblies\microsoft\framework\monoandroid\v1.0\facades\system.runtime.dll;c:\program files (x86)\reference assemblies\microsoft\framework\monoandroid\v1.0\system.xml.dll;c:\program files (x86)\reference assemblies\microsoft\framework\monoandroid\v1.0\system.xml.linq.dll       output files: obj\debug\resourcepaths.cache     done building target "_buildadditionalresourcescache" in project "droid2.csproj".     target "_getadditionalresourcesfromassemblies" in file "c:\program files (x86)\msbuild\xamarin\android\xamarin.android.common.targets":       task "readadditionalresourcesfromassemblycache"         task readadditionalresourcesfromassemblycache           cachefile: obj\debug\resourcepaths.cache           additionalandroidresourcepaths:            additionaljavalibraryreferences:            additionalnativelibraryreferences:            isvalid: true       done executing task "readadditionalresourcesfromassemblycache".       task "createitem" skipped, due false condition; (exists ('%(_additionalandroidresourcepaths.identity)\androidmanifest.xml')) evaluated (exists ('\androidmanifest.xml')).     done building target "_getadditionalresourcesfromassemblies" in project "droid2.csproj".     target "_calculateadditionalresourcecachedirectories" in file "c:\program files (x86)\msbuild\xamarin\android\xamarin.android.common.targets":       using "calculateadditionalresourcecachedirectories" task assembly "c:\program files (x86)\msbuild\xamarin\android\xamarin.android.build.tasks.dll".       task "calculateadditionalresourcecachedirectories"         calculateadditionalresourcecachedirectories task           additionalandroidresourcepaths:           cachedirectory: obj\debug\resourcecache       done executing task "calculateadditionalresourcecachedirectories".     done building target "_calculateadditionalresourcecachedirectories" in project "droid2.csproj".     target "_getadditionalresourcesfromassemblies" skipped. built successfully.     target "_createadditionalresourcecache" in file "c:\program files (x86)\msbuild\xamarin\android\xamarin.android.common.targets":       skipping target "_createadditionalresourcecache" because has no outputs.       though target has declared outputs, output specification references empty properties and/or empty item lists.     done building target "_createadditionalresourcecache" in project "droid2.csproj".     target "_resolvemonoandroidsdks" skipped. built successfully.     target "_generateandroidresourcedir" in file "c:\program files (x86)\msbuild\xamarin\android\xamarin.android.common.targets":       skipping target "_generateandroidresourcedir" because output files up-to-date respect input files.       input files: resources\layout\main.axml;resources\values\strings.xml;resources\drawable\icon.png;c:\program files (x86)\msbuild\14.0\bin\microsoft.csharp.currentversion.targets;d:\play app\droid2\droid2\droid2.csproj;c:\program files (x86)\msbuild\14.0\bin\microsoft.common.currentversion.targets;c:\program files (x86)\msbuild\14.0\bin\microsoft.xaml.targets;obj\debug\build.props       output files: d:\play app\droid2\droid2\obj\debug\res\layout\main.xml;d:\play app\droid2\droid2\obj\debug\res\values\strings.xml;d:\play app\droid2\droid2\obj\debug\res\drawable\icon.png     done building target "_generateandroidresourcedir" in project "droid2.csproj".     target "_updateandroidresgen" in file "c:\program files (x86)\msbuild\xamarin\android\xamarin.android.common.targets":       skipping target "_updateandroidresgen" because output files up-to-date respect input files.       input files: c:\program files (x86)\reference assemblies\microsoft\framework\monoandroid\v1.0\java.interop.dll;c:\program files (x86)\reference assemblies\microsoft\framework\monoandroid\v6.0\mono.android.dll;c:\program files (x86)\reference assemblies\microsoft\framework\monoandroid\v1.0\mscorlib.dll;c:\program files (x86)\reference assemblies\microsoft\framework\monoandroid\v1.0\system.core.dll;c:\program files (x86)\reference assemblies\microsoft\framework\monoandroid\v1.0\system.dll;c:\program files (x86)\reference assemblies\microsoft\framework\monoandroid\v1.0\facades\system.runtime.dll;c:\program files (x86)\reference assemblies\microsoft\framework\monoandroid\v1.0\system.xml.dll;c:\program files (x86)\reference assemblies\microsoft\framework\monoandroid\v1.0\system.xml.linq.dll;d:\play app\droid2\droid2\obj\debug\res\layout\main.xml;d:\play app\droid2\droid2\obj\debug\res\values\strings.xml;d:\play app\droid2\droid2\obj\debug\res\drawable\icon.png;c:\program files (x86)\msbuild\14.0\bin\microsoft.csharp.currentversion.targets;d:\play app\droid2\droid2\droid2.csproj;c:\program files (x86)\msbuild\14.0\bin\microsoft.common.currentversion.targets;c:\program files (x86)\msbuild\14.0\bin\microsoft.xaml.targets       output files: obj\debug\r.cs.flag     done building target "_updateandroidresgen" in project "droid2.csproj".     target "_addlibraryprojectsembeddedresourcetoproject" in file "c:\program files (x86)\msbuild\xamarin\android\xamarin.android.common.targets":       using "createmanagedlibraryresourcearchive" task assembly "c:\program files (x86)\msbuild\xamarin\android\xamarin.android.build.tasks.dll".       task "createmanagedlibraryresourcearchive"       done executing task "createmanagedlibraryresourcearchive".       task "createitem" skipped, due false condition; (exists ('$(intermediateoutputpath)__androidlibraryprojects__.zip')) evaluated (exists ('obj\debug\__androidlibraryprojects__.zip')).     done building target "_addlibraryprojectsembeddedresourcetoproject" in project "droid2.csproj".     target "_generatejavadesignerforcomponent" skipped, due false condition; ('@(_additonalandroidresourcecachepaths)' != '') evaluated ('' != '').     target "updateandroidresources" in file "c:\program files (x86)\msbuild\xamarin\android\xamarin.android.common.targets":     done building target "updateandroidresources" in project "droid2.csproj".     target "getreferenceassemblypaths" skipped. built successfully.     target "implicitlyexpanddesigntimefacades" in file "c:\program files (x86)\msbuild\xamarin\android\xamarin.android.pclsupport.targets":       task "message" skipped, due false condition; ('%(referencepath.resolvedfrom)' == 'implicitlyexpanddesigntimefacades') evaluated ('{targetframeworkdirectory}' == 'implicitlyexpanddesigntimefacades').       task "message" done executing task "message".     done building target "implicitlyexpanddesigntimefacades" in project "droid2.csproj".     target "resolvereferences" in file "c:\program files (x86)\msbuild\14.0\bin\microsoft.common.currentversion.targets":     done building target "resolvereferences" in project "droid2.csproj".     target "resolvekeysource" skipped, due false condition; ($(signmanifests) == 'true' or $(signassembly) == 'true') evaluated ( == 'true' or  == 'true').     target "resolvecomreferences" skipped, due false condition; ('@(comreference)'!='' or '@(comfilereference)'!='') evaluated (''!='' or ''!='').     target "resolvenativereferences" skipped, due false condition; ('@(nativereference)'!='') evaluated (''!='').     target "_setexternalwin32manifestproperties" skipped, due false condition; ('$(generateclickoncemanifests)'=='true' or '@(nativereference)'!='' or '@(resolvedisolatedcommodules)'!='') evaluated (''=='true' or ''!='' or ''!='').     target "_setembeddedwin32manifestproperties" in file "c:\program files (x86)\msbuild\14.0\bin\microsoft.common.currentversion.targets":       using "getframeworkpath" task assembly "microsoft.build.tasks.core, version=14.0.0.0, culture=neutral, publickeytoken=b03f5f7f11d50a3a".       task "getframeworkpath"       done executing task "getframeworkpath".     done building target "_setembeddedwin32manifestproperties" in project "droid2.csproj".     target "setwin32manifestproperties" in file "c:\program files (x86)\msbuild\14.0\bin\microsoft.common.currentversion.targets":     done building target "setwin32manifestproperties" in project "droid2.csproj".     target "_generatecompileinputs" in file "c:\program files (x86)\msbuild\14.0\bin\microsoft.common.currentversion.targets":       task "warning" skipped, due false condition; ('@(manifestresourcewithnoculture)'!='' , '%(manifestresourcewithnoculture.emittedforcompatibilityonly)'=='') evaluated (''!='' , ''=='').       task "warning" skipped, due false condition; ('@(manifestnonresxwithnocultureondisk)'!='' , '%(manifestnonresxwithnocultureondisk.emittedforcompatibilityonly)'=='') evaluated (''!='' , ''=='').     done building target "_generatecompileinputs" in project "droid2.csproj".     target "prepareforbuild" skipped. built successfully.     target "getreferenceassemblypaths" skipped. built successfully.     target "_settargetframeworkmonikerattribute" in file "c:\program files (x86)\msbuild\14.0\bin\microsoft.csharp.currentversion.targets":     done building target "_settargetframeworkmonikerattribute" in project "droid2.csproj".     target "generatetargetframeworkmonikerattribute" in file "c:\program files (x86)\msbuild\14.0\bin\microsoft.common.currentversion.targets":       skipping target "generatetargetframeworkmonikerattribute" because output files up-to-date respect input files.       input files: c:\program files (x86)\msbuild\14.0\bin\microsoft.common.targets       output files: c:\users\ids\appdata\local\temp\monoandroid,version=v6.0.assemblyattributes.cs     done building target "generatetargetframeworkmonikerattribute" in project "droid2.csproj".     target "generateadditionalsources" skipped, due false condition; ('@(assemblyattributes)' != '' , '$(generateadditionalsources)' == 'true') evaluated ('' != '' , '' == 'true').     target "beforecompile" in file "c:\program files (x86)\msbuild\14.0\bin\microsoft.common.currentversion.targets":     done building target "beforecompile" in project "droid2.csproj".     target "_timestampbeforecompile" skipped, due false condition; ('$(runpostbuildevent)'=='onoutputupdated' or ('$(registerforcominterop)'=='true' , '$(outputtype)'=='library')) evaluated (''=='onoutputupdated' or (''=='true' , 'library'=='library')).     target "generatecompiledexpressionstempfile" in file "c:\windows\microsoft.net\framework\v4.0.30319\microsoft.workflowbuildextensions.targets":       task "writelinestofile" skipped, due false condition; (!exists('$(generatecompiledexpressionstempfilepathforediting)')) evaluated (!exists('obj\debug\\temporarygeneratedfile_e7a71f73-0f8d-4b9b-b56e-8e70b10bc5d3.cs')).       task "writelinestofile" skipped, due false condition; (!exists('$(generatecompiledexpressionstempfilepathforvalidation)')) evaluated (!exists('obj\debug\\temporarygeneratedfile_036c0b5b-1481-4323-8d20-8f5adcb23d92.cs')).       task "writelinestofile" skipped, due false condition; (!exists('$(generatecompiledexpressionstempfilepathfortypeinfer)')) evaluated (!exists('obj\debug\\temporarygeneratedfile_5937a670-0e60-4077-877b-f7221da3dda1.cs')).     done building target "generatecompiledexpressionstempfile" in project "droid2.csproj".     target "designtimexamlmarkupcompilation" in file "c:\windows\microsoft.net\framework\v4.0.30319\microsoft.xaml.targets":       task "makedir" skipped, due false condition; ('@(xamlappdef)' != '') evaluated ('' != '').       task "calltarget" skipped, due false condition; ('$(buildingproject)' != 'true' , '@(xamlappdef)' != '') evaluated ('false' != 'true' , '' != '').     done building target "designtimexamlmarkupcompilation" in project "droid2.csproj".     target "cleaninprocessxamlgeneratedfiles" skipped, due false condition; ('@(xamlappdef)' != '') evaluated ('' != '').     target "_computenonexistentfileproperty" in file "c:\program files (x86)\msbuild\14.0\bin\microsoft.common.currentversion.targets":     done building target "_computenonexistentfileproperty" in project "droid2.csproj".     target "resolvecodeanalysisruleset" in file "c:\program files (x86)\msbuild\14.0\bin\microsoft.csharp.currentversion.targets":       using "resolvecodeanalysisruleset" task assembly "microsoft.build.tasks.core, version=14.0.0.0, culture=neutral, publickeytoken=b03f5f7f11d50a3a".       task "resolvecodeanalysisruleset"       done executing task "resolvecodeanalysisruleset".     done building target "resolvecodeanalysisruleset" in project "droid2.csproj".     target "prexsdcodegen" in file "c:\windows\microsoft.net\framework\v4.0.30319\microsoft.servicemodel.targets":       using "calltarget" task assembly "microsoft.build.tasks.core, version=14.0.0.0, culture=neutral, publickeytoken=b03f5f7f11d50a3a".       task "calltarget"         target "cleanxsdcodegen" in file "c:\windows\microsoft.net\framework\v4.0.30319\microsoft.servicemodel.targets":           using "delete" task assembly "microsoft.build.tasks.core, version=14.0.0.0, culture=neutral, publickeytoken=b03f5f7f11d50a3a".           task "delete"           done executing task "delete".         done building target "cleanxsdcodegen" in project "droid2.csproj".       done executing task "calltarget".     done building target "prexsdcodegen" in project "droid2.csproj".     target "xsdcodegen" skipped, due false condition; ( '$(xsdcodegenprecondition)' == 'true' ) evaluated ( 'false' == 'true' ).     target "corecompile" in file "c:\program files (x86)\msbuild\14.0\bin\microsoft.csharp.core.targets":       building target "corecompile" completely.       output file "obj\debug\droid2.dll" not exist.       using "csc" task assembly "c:\users\ids\appdata\local\microsoft\visualstudio\14.0\extensions\enunflvr.wib\microsoft.build.tasks.codeanalysis.dll".       task "csc"         c:\program files (x86)\msbuild\14.0\bin\microsoft.csharp.core.targets(76,11): error msb4064: "checksumalgorithm" parameter not supported "csc" task. verify parameter exists on task, , settable public instance property.         c:\program files (x86)\msbuild\14.0\bin\microsoft.csharp.core.targets(67,5): error msb4063: "csc" task not initialized input parameters.        done executing task "csc" -- failed.     done building target "corecompile" in project "droid2.csproj" -- failed.      done building project "droid2.csproj" -- failed.      project performance summary:           125 ms  d:\play app\droid2\droid2\droid2.csproj    1 calls      target performance summary:             0 ms  _addmultidexdependencyjars                 1 calls             0 ms  resolvesdkreferences                       1 calls             0 ms  _setupdesigntimebuildforintellisense       1 calls             0 ms  getinstalledsdklocations                   1 calls             0 ms  getreferenceassemblypaths                  1 calls             0 ms  _validateandroidpackageproperties          1 calls             0 ms  _checkforinvalidconfigurationandplatform   1 calls             0 ms  resolvereferences                          1 calls             0 ms  assignprojectconfiguration                 1 calls             0 ms  _generatecompileinputs                     1 calls             0 ms  _buildadditionalresourcescache             1 calls             0 ms  _resolvelibraryprojectimports              1 calls             0 ms  _buildsdkcache                             1 calls             0 ms  generatetargetframeworkmonikerattribute    1 calls             0 ms  resolveprojectreferences                   1 calls             0 ms  getframeworkpaths                          1 calls             0 ms  _calculateadditionalresourcecachedirectories   1 calls             0 ms  afterresolvereferences                     1 calls             0 ms  _setembeddedwin32manifestproperties        1 calls             0 ms  _checkduplicatejavalibraries               1 calls             0 ms  _getlibraryimports                         1 calls             0 ms  _generateandroidassetsdir                  1 calls             0 ms  _resolvemonoandroidframework               1 calls             0 ms  _separateappextensionreferences            1 calls             0 ms  _splitprojectreferencesbyfileexistence     1 calls             0 ms  _buildlibraryimportscache                  1 calls             0 ms  _computenonexistentfileproperty            1 calls             0 ms  _generateandroidresourcedir                1 calls             0 ms  setwin32manifestproperties                 1 calls             0 ms  beforeresolvereferences                    1 calls             0 ms  _getreferenceassemblypaths                 1 calls             0 ms  cleanxsdcodegen                            1 calls             0 ms  _updateandroidresgen                       1 calls             0 ms  modifyunittestplatformversion              1 calls             0 ms  _computeandroidresourcepaths               1 calls             0 ms  _settargetframeworkmonikerattribute        1 calls             0 ms  _addlibraryprojectsembeddedresourcetoproject   1 calls             0 ms  updateandroidresources                     1 calls             0 ms  expandsdkreferences                        1 calls             0 ms  beforecompile                              1 calls             0 ms  prepareforbuild                            1 calls             0 ms  prexsdcodegen                              1 calls             0 ms  _extractlibraryprojectimports              1 calls             0 ms  resolvecodeanalysisruleset                 1 calls             0 ms  _computeandroidassetspaths                 1 calls             0 ms  designtimexamlmarkupcompilation            1 calls             0 ms  _checkfordeletedresourcefile               1 calls             0 ms  _createadditionalresourcecache             1 calls             0 ms  _getadditionalresourcesfromassemblies      1 calls             0 ms  generatecompiledexpressionstempfile        1 calls             0 ms  updateandroidassets                        1 calls            16 ms  _resolvemonoandroidsdks                    1 calls            16 ms  implicitlyexpanddesigntimefacades          1 calls            16 ms  _validateresourcecache                     1 calls            16 ms  corecompile                                1 calls            31 ms  _setlatesttargetframeworkversion           1 calls            31 ms  resolveassemblyreferences                  1 calls      task performance summary:             0 ms  createitem                                 1 calls             0 ms  calltarget                                 1 calls             0 ms  findappconfigfile                          1 calls             0 ms  getandroidpackagename                      1 calls             0 ms  createproperty                            39 calls             0 ms  readimportedlibrariescache                 1 calls             0 ms  csc                                        1 calls             0 ms  createmanagedlibraryresourcearchive        1 calls             0 ms  checkduplicatejavalibraries                1 calls             0 ms  resolvecodeanalysisruleset                 1 calls             0 ms  getreferenceassemblypaths                  2 calls             0 ms  getappsettingsdirectory                    1 calls             0 ms  message                                   13 calls             0 ms  delete                                     1 calls             0 ms  makedir                                    2 calls             0 ms  readlibraryprojectimportscache             1 calls             0 ms  getframeworkpath                           1 calls             0 ms  readresolvedsdkscache                      1 calls             0 ms  androidcomputerespaths                     2 calls             0 ms  getjavaplatformjar                         1 calls             0 ms  calculateadditionalresourcecachedirectories   1 calls             0 ms  assignprojectconfiguration                 1 calls            16 ms  getandroiddefineconstants                  1 calls            16 ms  readadditionalresourcesfromassemblycache   2 calls            31 ms  resolveassemblyreference                   1 calls      build failed.      c:\program files (x86)\msbuild\14.0\bin\microsoft.csharp.core.targets(76,11): error msb4064: "checksumalgorithm" parameter not supported "csc" task. verify parameter exists on task, , settable public instance property.     c:\program files (x86)\msbuild\14.0\bin\microsoft.csharp.core.targets(67,5): error msb4063: "csc" task not initialized input parameters.          0 warning(s)         2 error(s)      time elapsed 00:00:00.14 

i had same issue after update 3 , proj file had correct order. co-worker helped me troubleshoot. turned out had roslyn insiders extension installed , high-jacking compiler. once removed extension, worked fine again.