Tips and Tricks for:  Visual Basic.Net 2003

The Problem:   VB.Net compiler error: BC31091 Import of type '<unknown>' from assembly '<unknown>' failed.

This error is accompanied by a cascade of related errors that result once the type of your variable can't be determined.

Solution: Peg the version number of the assemblies in your solution.

I must say, I don't know why this works but it seems to.  What I do is peg (hard code) the assembly version of all the assemblies in my solution.  This seemed to make the error go away.  So I use it.  I suspect that at some point the size off the assemblies has caused the compiler to run into an error that didn't effect the solution when the assemblies were smaller but I don't know this for a fact.

In your AssemblyInfo.vb files, in all your other projects change this:

<Assembly: AssemblyVersion("1.0.*")>
 

Into this:

<Assembly: AssemblyVersion("1.0.10.0")>

All that I've changed is the version number to a hard coded number.  The number doesn't matter, use whatever makes sense in your project.