TeamCity 8.0.6 CI box with build agent has been purring along for several years. After a system restart, TeamCity seems to have auto-upgraded the local build agent to version 27767. No other configuration changes were made, but this error now shows on build trigger:
Unable to find MSBuild at C:\Windows\Microsoft.NET\Framework\v4.0.30319\MSBuild.exe, please check MSBuild environment variable to target to Microsoft .NET Framework 2.0/3.5/4.0 or Mono installation directory
I RDP'd into the box and see that MSBuild.exe went missing - strange. So I re-add it from a local install and retrigger a build. As soon as the build agent picks up the file, it disappears! Happens every time. Maybe Windows is protecting this folder?
The build agent then becomes "incompatible". I tried this workaround, but this doesn't stop msbuild.exe
from being deleted.
I checked that there are no odd steps in my build configuration. What could be deleting or moving MSBuild?