Director 12 crashes when opening movie since Hotfix 4

Since updating to Hotfix 4, 90% of my .dir movies make Director "Unexpectdly Quit" when I try to open them, as soon as the stage appears.

I'm running Mac OS X 10.9.2 (Mavericks).

I tried to reinstall Director 12, which solved the bug, until I reapplied Hotfix 4 and now the same thing happens.

There's no way to revert to HotFix 3, and without any hotfixes Director 12 can't even publish iOS apps.

So, I'm pretty much screwed. Will I have to wait 6 months until Hotfix 5 fixes this?

Edit : Even if I don't open a movie, Director randomly quits after doing almost anything!