MonoDevelop can't import VS2013/2015 solutions

Question

I'm opening a .sln file that I transferred from VS2013 into MonoDevelop. When I attempt this, however, it gives me the following error(s):

1. Project 'foo' has a different ToolsVersion than the containing solution.
2. Error while trying to load the project '/path/to/foo.csproj': Unknown ToolsVersion '12.0'
3. [repeat 2 for every project in the solution]

When I tried doing this for a VS2015 file, it game me the same errors, except this time ToolsVersion was 14.0.

My MonoDevelop version is v4.0.12; is there a workaround for this?

Answer 1

Workarounds are:

1. Upgrade to MonoDevelop 5 which supports projects that use Tools Version 12.0

2. Edit the .csproj file and change the Tools Version to 4.0

   <Project ToolsVersion="4.0"

If you opt for 2. then you will have to see if the project still builds after this change.

Answer 2

I know MonoDevelop 5.x+ / Mono 4.x has xbuild/MSBuild support Toolsversion 12. So let check your installation.

Check Mono install:

mono --version

Mono JIT compiler version 4.0.2 ((detached/c99aa0c Thu Jun 11 18:53:01 EDT 2015)

xbuild --version

XBuild Engine Version 12.0
Mono, Version 4.0.2.0**

Check your GAC installation:

gacutil -l |grep Microsoft.Build

Microsoft.Build, Version=12.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
Microsoft.Build, Version=14.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
Microsoft.Build, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
Microsoft.Build.Engine, Version=12.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
Microsoft.Build.Engine, Version=14.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
Microsoft.Build.Engine, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
Microsoft.Build.Framework, Version=12.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
Microsoft.Build.Framework, Version=14.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
Microsoft.Build.Framework, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
Microsoft.Build.Tasks.Core, Version=14.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
Microsoft.Build.Tasks.v12.0, Version=12.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
Microsoft.Build.Tasks.v4.0, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
Microsoft.Build.Utilities.Core, Version=14.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
Microsoft.Build.Utilities.v12.0, Version=12.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
Microsoft.Build.Utilities.v4.0, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a

Check if you have the MSBuild dll (paths are platform dependent also, change as needed):

cat `which xbuild`

#!/bin/sh
exec /Library/Frameworks/Mono.framework/Versions/4.0.2/bin/mono $MONO_OPTIONS /Library/Frameworks/Mono.framework/Versions/4.0.2/lib/mono/xbuild/12.0/bin/xbuild.exe "$@"

Grab your Mono install path from the output above and change the path below to match:

find /Library/Frameworks/Mono.framework/Versions/4.0.2 -name "*MSBuild"

/Library/Frameworks/Mono.framework/Versions/4.0.2/lib/mono/4.5/MSBuild
/Library/Frameworks/Mono.framework/Versions/4.0.2/lib/mono/gac/Mono.Addins.MSBuild
/Library/Frameworks/Mono.framework/Versions/4.0.2/lib/mono/gac/policy.0.2.Mono.Addins.MSBuild
/Library/Frameworks/Mono.framework/Versions/4.0.2/lib/mono/gac/policy.0.3.Mono.Addins.MSBuild
/Library/Frameworks/Mono.framework/Versions/4.0.2/lib/mono/gac/policy.0.4.Mono.Addins.MSBuild
/Library/Frameworks/Mono.framework/Versions/4.0.2/lib/mono/gac/policy.0.5.Mono.Addins.MSBuild
/Library/Frameworks/Mono.framework/Versions/4.0.2/lib/mono/gac/policy.0.6.Mono.Addins.MSBuild
/Library/Frameworks/Mono.framework/Versions/4.0.2/lib/mono/xbuild/12.0/bin/MSBuild
/Library/Frameworks/Mono.framework/Versions/4.0.2/lib/mono/xbuild/14.0/bin/MSBuild

So as you can see I have Tools version 12. Update your install / Re-install as needed ;-)