Also posted this here.
Having an issue where after installing 10.1 debug build and then stepping back to 10.0 debug on Windows 7 and Flash Builder 4 the debugger will no longer connect:
After 1-2 minutes it times out with Launch Failed: Failed to connect; session timed out. Esnure that: 1. You compiled your Flash application with debugging on. 2. You are running the debugger version of Flash Player.
Any thoughts on what may be happening here? Nothing else has changed and after searching for quite a while for answers nothing has resolved the issue.
Can you run flash content? Go to one of the sites that tells you whether
you have a debugger player or not.