I am having the same problem. I get a big red X on my Toolbox, which means I am unable to open it and even view the potential errors within them. However, when I click "Check Syntax" I get "No Syntax Errors". What does this mean? If there are no syntax errors, what is the problem? If there is an error, why doesn't it tell me where it is? As a test, I added an error, and it was returned when I reclicked "Check Syntax". This seems in all respects to be a bug.