this trick worked for me:
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!
Update: Looks like in workspaces created by Flash Builder 4.5 this file doesn’t exist. If I ever break a FB 4.5 workspace I’ll have to start looking for a solution all over again )8
(taken from Valentin Simonov's blog http://va.lent.in/blog/2010/07/12/how-to-fix-flash-builder-broken-work space/)
I have no idea why this needs to be done in order for my program to work properly, but this did get it going.
Followed mugdha's instructions a little less strictly and got Flash Builder 4.6 to start up.
1) Opened Encore > Deactivated
2) Closed Encore.
3) Opened Encore > Entered my CS6 serial and signed in.
4) Closed Encore.
5) Opened Flash Builder 4.6 with success.
I don't know if anyone is still using Flash...haha , but another way to do it is to:
Uninstall FB - check unstall preferences.
Go to your original install dmz and start the install process.
When the install shows you your serial number with the last four XXXX, reinter your whole serial number.
(I tried installing without entering in all the serial number and relying on it remembering, but it didn't change the problem outlined in this thread.
You will be prompted to sign in
Select FB ( I happened to have Dreamweaver checked also, so it was installed also...you may want to select some other compontent that is not installed)
Since Dreamweaver installed along with it, I decided to open it first. Don't know if that made any difference, but I wanted to show every step that I did.
FB opened fine after that.
I hope this helps someone.
Same issue with Flash Builder 4.7, running OS X 10.7.5.
I also have installed CS5.5 which includes Flash Builder 4.5
Just started immediately crashing on launch yesterday.
De-activate, reactivate CS5.5 did nothing and regardless, I don't consider reinstalling / reactivating software a "fix". More like a klugy workaround at best.
What's the official word on this...
It's been about a year since this has been reported; is anyone actively looking into a real fix (e.g., determining why the software is doing this.)?