If you got problems with Firefox – no matter if it’s Windows, Linux or anything else – it is always a good idea to kill its configs. How come?

The problem started after updating Firefox in my Windows-VM. What now? Alright… downgrading as it used to work with the previous version.

Murphys law strikes back – this did not work. Using IE? Only over my dead body. The solution was brought by Gentoo linux just by doing the update there. This message was a clue:

* Please remember to rebuild any packages that you have built
* against firefox. Some packages might be broken by the upgrade; if this
* is the case, please search at http://bugs.gentoo.org and open a new bug
* if one does not exist. Before filing any bugs, please move or remove ~/.mozilla
* and test with a clean profile directory.

So I removed all of Firefox configs and caches in my profile directory and installed the latest version and everything works again.

Lesson learned: For solving some windows problems you have to look at linux.