Everybody doing serious workflow development using Windows Workflow Foundation has probably experienced first hand that the workflow designer hosted by Visual Studio is not the most stable application ever. Every now and then you get unexplainable errors, while you didn't do anything you'd expect to be remotely responsible for trashing the WF-designer. It not just annoying, it can be very irritating and - believe me - even ruin your day!
Solving those issues it probably even harder than causing them, although after a while you do get more creative. I've worked with the WF-designer for over 2 years now and have come up with a solution that in my case solves most of those problems:
- Close all instances of Visual Studio (including products like SQL Server Management Studio)
- Remove all temp-files created by Visual Studio (using the cmd-file attached to this article)
- Remove the <solution>.suo (same folder as the solution-file itself)
Although the WF-designer gets better every release of Visual Studio or its service packs, it's still far from perfect. Since we're probably stuck with it for some time, I hope this post will help a few people to save their day! ;)
NB: The attached cmd-file contains a version-number of Visual Studio. Check to see if it matches with the version of Visual Studio you're using (eg: 8.0=VS 2005)