Got this error while setting up my new working environment.
For some reason I skipped Mono and .NET installations while installing and configuring Rider. This seems to have caused some misconfiguration in Rider. So the solution for me (Mac) was simple:
- Open Rider
- Go to “Preferences/Build, Execution, Deployment”
- Then “Toolset and Build”
You might notice on the right, that MSBuild – which is basically the build tool responsible for getting things done in Rider – is set to a lower version. For instance, mine was set to “15” coming from Mono’s installation folder, while I had “17” available from my .NET installation folder. Selecting .NET’s 17 version did the trick, no more errors in Rider’s “Problems” tab.