Fix MissingMethodException thrown (internally) when loading projects

build/Targets/Settings.props

@@ -41,7 +41,7 @@
     <TargetFrameworkRootPath>$(NuGetPackageRoot)\RoslynTools.ReferenceAssemblies\$(RoslynToolsReferenceAssembliesVersion)\tools\Framework</TargetFrameworkRootPath>
 
     <VisualStudioVersion Condition="'$(VisualStudioVersion)' == ''">15.0</VisualStudioVersion>
-    <VisualStudioReferenceMajorVersion Condition="'$(VisualStudioReferenceMajorVersion)' == ''">$(VisualStudioVersion.Substring(0, $(VisualStudioVersion.IndexOf('.'))))</VisualStudioReferenceMajorVersion>
+    <VisualStudioReferenceMajorVersion Condition="'$(VisualStudioReferenceMajorVersion)' == ''">$(VisualStudioVersion.Substring($([System.Convert]::ToInt32(0)), $(VisualStudioVersion.IndexOf('.'))))</VisualStudioReferenceMajorVersion>
     <VisualStudioReferenceAssemblyVersion Condition="'$(VisualStudioReferenceAssemblyVersion)' == ''">$(VisualStudioReferenceMajorVersion).0.0.0</VisualStudioReferenceAssemblyVersion>
     <VisualStudioCodename>Dev$(VisualStudioReferenceMajorVersion)</VisualStudioCodename>
     <MinimumVisualStudioVersion>$(VisualStudioVersion)</MinimumVisualStudioVersion>

build/Targets/Versions.props

@@ -28,7 +28,7 @@
          can still be deployed to VS and override the version that is globally installed. -->
     <BuildNumber Condition="'$(BuildNumber)' == ''">00065535.0</BuildNumber>
     <!-- When a build number is specified, it needs to be in the format of 'x.y'-->
-    <Error Condition="$(BuildNumber.Split('.').Length) != 2">BuildNumber should have two parts (in the form of 'x.y')</Error>
+    <Error Condition="$(BuildNumber.Split($([System.Convert]::ToString(`.`).ToCharArray())).Length) != 2">BuildNumber should have two parts (in the form of 'x.y')</Error>
 
     <!-- Split the build parts out from the BuildNumber which is given to us by MicroBuild in the format of yyyymmdd.nn
          where BuildNumberFiveDigitDateStamp is mmmdd (such as 60615) and BuildNumberBuildOfTheDay is nn (which represents the nth build
@@ -38,8 +38,8 @@
          Additionally, in order ensure the value fits in the 16-bit PE header fields, we will only take the last five digits of the BuildNumber, so
          in the case of 20160615, we will set BuildNumberFiveDigitDateStamp to 60615. Unfortunately for releases in 2017 we can't go any higher, so
          well continue the month counting instead: the build after 61231 is 61301. -->
-    <BuildNumberFiveDigitDateStamp>$([MSBuild]::Subtract($(BuildNumber.Split('.').GetValue($([System.Convert]::ToInt32(0))).Substring(3).Trim()), 8800))</BuildNumberFiveDigitDateStamp>
-    <BuildNumberBuildOfTheDayPadded>$(BuildNumber.Split('.').GetValue($([System.Convert]::ToInt32(1))).PadLeft(2,'0'))</BuildNumberBuildOfTheDayPadded>
+    <BuildNumberFiveDigitDateStamp>$([MSBuild]::Subtract($([System.Convert]::ToInt32($(BuildNumber.Split($([System.Convert]::ToString(`.`).ToCharArray())).GetValue($([System.Convert]::ToInt32(0))).Substring($([System.Convert]::ToInt32(3))).Trim())), $([System.Convert]::ToInt32(8800))))</BuildNumberFiveDigitDateStamp>
+    <BuildNumberBuildOfTheDayPadded>$(BuildNumber.Split($([System.Convert]::ToString(`.`).ToCharArray())).GetValue($([System.Convert]::ToInt32(1))).PadLeft($([System.Convert]::ToInt32(2)), $([System.Convert]::ToChar(`0`))))</BuildNumberBuildOfTheDayPadded>
 
     <!-- NuGet version -->
     <NuGetReleaseVersion>$(RoslynFileVersionBase)</NuGetReleaseVersion>