Research so far indicates that this is caused by corrupt extension archives, most likely caused by Mozilla's server-side signing procedure introducing errors in the JAR archives that extensions are packed in. These corrupted archive packages will trigger a crash in Pale Moon (and older Firefox versions alike) that are sensitive to this type of signed archive corruption. Manually signed extension packages have always been just fine, so as far as we can tell it is Mozilla's server-side signing procedure that introduces the error.
UPDATE: We have now successfully halted the automatic faulty updates being served through our add-ons server, so the steps below have become optional (although still required if you are using an older version of Pale Moon).
Once again, to be clear: This is a direct result of a problem in Firefox extension packages as served by Mozilla. It is not caused by a Pale Moon update or otherwise an error in the browser (just being a little less robust when encountering corrupted signed installation files).
What to do if you experience sudden crashes:
- Go to Add-Ons (add-on manager) in the menu (or press Ctrl+Shift+A)
- Click the gear at the top
- Uncheck "Update add-ons automatically"