can you check this issue on Firefox 13?

• getfirefox.com

See also:

• http://kb.mozillazine.org/Firefox_crashes
• https://support.mozilla.org/kb/Firefox+crashes

Create a new profile as a test to check if your current profile is causing the problems.

See "Basic Troubleshooting: Make a new profile":

• https://support.mozilla.org/kb/Basic+Troubleshooting#w_8-make-a-new-profile

There may be extensions and plugins installed by default in a new profile, so check that in "Tools > Add-ons > Extensions & Plugins" in case there are still problems.

If the new profile works then you can transfer some files from the old profile to that new profile, but be careful not to copy corrupted files.

See:

• http://kb.mozillazine.org/Transferring_data_to_a_new_profile_-_Firefox

Firefox 13 gives me another error:

 XPCOMGlueLoad error for file /opt/firefox13/libxpcom.so:
 libxul.so: cannot open shared object file: No such file or directory
 Couldn't load XPCOM.

(I followed the guide at this link)

I tried following the advices in your links, updating anything that could be updated, but results didn't change (I also tried a clean re-install of firefox, but it didn't solve the problem).

About profiles, I might be misunderstanding you, but I can't access my firefox profile since firefox crashes as soon as I launch it.

@cor-el: sorry, I just created a new profile using firefox -no-remote ProfileManager and it actually solved the startup crash.

Thank you very much for your time (to both of you),

--
nadirs

You're welcome