From time to time I get weird Flash Builder/OS X crashes which lead to Flash Builder (Eclipse) freeze or hang up during startup. You think you have to recreate your workspace every time after a crash, but no, if that happens there’s a solution.
So, if Flash Builder freezes trying to load your workspace what you need to do to fix it is to navigate to
.metadata/.plugins/org.eclipse.core.resources and delete the file named
.snap. That’s it. No more rearranging views and reimporting projects!