This is a new issue that just cropped up for me that I did not used to have. It seems to have occurred roughly the same time as I began having some issues with Reader X, if that helps shed any light. Anyway, what happens is I start flash pro, and it goes to "Building Workspace" right before a pop-up comes and sayts "An error occurred opening file'C:\Users\*My username*\AppData\Local\Flash CS5\en_US\Tools\Polystar.jsfl." I click ok and I get a Visual C++ Runtime Library runtime error. If I try to reinstall Flash it says it couldn't install fully. I am so confused, I don't know whats going on. Can anyone shed any light on my problem?