You should only get this when you're debugging. In production it shouldn't happen.
What the message is telling you is that the VB project you clicked on is busy with a synchronous call to another object. If you click on the "Switch to" button, it should take you there. Depending on how many projects are involved, you might have to do it several times to get to the one that is actually doing work.
If you get to the end of the call chain, and the project there isn't responding, that's because it's made a synchronous (blocking) call to some other COM service or Win32 API call. You can hit Ctrl-Break, and when that call gets completed the IDE will break execution at the next line. If it never comes back, then it's either stuck in an infinite loop, or there's a resource deadlock. You'll need to troubleshoot that.
Chip H.
