You will have problems with this since .NET 4 works with the new version of the CLR runtime.
I think your best and safest bet would be to try and compile a project for Framework 3.5. Of course, this depends on the size and features you used, but I donβt think you should have a lot of problems with the conversion. Of course, if you rely heavily on new features, such as dynamic ones, this may not be so simple.
source share