Mozilla Firefox is considered as the fastest browser that provides complete assurance of security and easy search. However, you may get some issues from time to time due to several other reasons. You can remove this issue by following this solution:
1. Try to manually update Mozilla Firefox.
2. Check for updates and install it on your computer.
3. You can try running Firefox as an administrator.
4. Clear all the caches and cookies from the browser.
5. Update your windows.
6. Scan your computer using the third-party antivirus software.
In case you are still getting some issues, then you should call at mozilla firefox customer care number for further help.