After messing with this some, I figure that this issue has something to do with deployment of the necessary files. Even though I have all these projects in one solution, and the second project with the user control works correctly, the third project with the windows form is missing something. I made sure that the windows form project had references to all the same devexpress and devforce assemblies that the project with the user control has. This helped but didn't fix the problem. I'm getting a similar message but with different errors. Here is another picture of what I'm getting.