Hello lalalei2001

check it in Safe Mode, in Safe Mode window select "Start in Safe Mode" and see if this happen again, if not see: Troubleshoot extensions, themes and hardware acceleration issues to solve common Firefox problems

thank you

Please mark "Solved" the answer that really solve the problem, to help others with a similar problem.

Neither of those two options worked.

Can you attach a screenshot?

How do I create a screenshot of my problem?

Use a compressed image type like PNG or JPG to save the screenshot.

There are other things that need your attention.

Your system details list shows that you have three Flash plugins installed.
You should only keep the most recent version and remove the others.

1. Shockwave Flash 11.4 r402
2. Shockwave Flash 11.3 r300
3. Shockwave Flash 11.2 r202

You can set the plugin.expose_full_path pref to true on the about:config page to see the full path of plugins on the about:plugins page.

• http://kb.mozillazine.org/Issues_related_to_plugins#Identifying_installed_plugins
• http://kb.mozillazine.org/about:plugins
• http://kb.mozillazine.org/about:config

It is best not to leave that pref set to true as it exposes that full path to web servers via the navigator.plugins object, so reset that pref to false after you are done with the about:plugins page.

See "Manually uninstalling a plugin":

• https://support.mozilla.org/kb/Troubleshooting+plugins