v11.0\WebApplications\Microsoft.WebApplication.targets was not found when file actually references v10

Question

First some background. At the end of 2012 we migrated our vs2008 solution to vs2010 but we still target .NET 3.5. (I know nothing but the latest and greatest here!)

Answer 1

I got this error in the end of November without making any changes to either the configuration of my TeamCity installation or MSBuild installation or the source code. On my build server Visual Studio isn't even installed, and the change from VS2010 to VS2012 was made in the end of August without any problems at the time.

My MSBuild version is 4.0.30319.18408, my build server is a Windows Server 2008 R2 SP1 with TeamCity v6.5.3.

I solved the issued by simply copying the v11-folder from another build server which was unaffected.

My guess is that this could have happened in two ways:

1. Something was updated which triggered a deletion of the v11-folder. Could it be a Windows Update to .NET or something?

2. Something was updated which changed my TeamCity/MSBuild configuration from using v10 to v11 and the builds stop working as the v11 never existed.

I've got a update to .NET Framework 4.5.1 on December 3rd, could that be the reason?

Brgds

Jonas