Visual Studio 2010: Could not resolve mscorlib for target framework '.NETFramework,Version=v4.0'

Question

We are currently migrating all our solutions from 2005 to 2010 (that\'s right, we\'re skipping 2008!). We are also changing our file structure to make some more sense (some

Answer 1

Microsoft Visual Basic for Applications Extensibility 5.3 (VBIDE) is the name of the devil!!!

Apparently this is a reference which my co-worker had somehow, but i didn't and because of this reference, EVERYTHING died. We discovered this because if you check "Show all files" on the specific project (which is a VB.NET project) you get the sweet References folder, which is normally not there for VB.Net project it's seems. Where the Tab failed us, the folder showed us one reference with a warning. Apparently this is something the compiler or VS2010 couldn't tell me but was exactly what was messing it up for us.

So, if you get this error when working on a project, "Show all files" so you get to see the References folder, and find out which reference could be causing your problems!

I'm glad it found this though, after more then 3 hours!! >.<