In that case, you might wanna try investigating more deeply.
1. Run firefox -safe-mode, and open with the screwed profile.
2. In the dialog box, pick to Disable ALL add-on components.
3. Run the screwed profile, and enable the add-ons backwards in time one by one, i.e. enable the oldest one, try the browser.
4. If no crash happens, enable the next oldest one, restart and try the browser again.
5. Repeat step 4 ad-infinitum until the last add-on you enable crashes the system.
You can either do that, or simply load the screwed profile in Safe Mode, export your bookmarks, and import them on the new profile. I'd go with the longer solution, since it ensures your sessions and history remain safe. It's a bit more tedious, but it's worth it.