hello zangaram, from another user we found out that this might be related to malware active on your pc. please close all firefox windows and try running firefox in safemode (by pressing the shift key while you're starting it). in firefox safemode go to firefox > addons > extensions and remove the entry named "Codec v1.0" or any other addons that look suspicious (toolbars etc.) & you have not installed intentionally. afterwards see if you can run firefox normally again...

please also do an in-depth scan of your system with the security software already in place and/or a different tool like the free version of malwarebytes & keep firefox and your plugins up-to-date in order to stay safe on the web.

Troubleshoot Firefox issues caused by malware

Update Firefox to the latest release

https://www.mozilla.org/plugincheck/

Thank you for the suggestions, but instead, I restored my system to 2 days before when all was working properly. It is all working now. The only major thing that happened in those two days was an installation of Java update. I am wondering if that has a conflict with Firefox. I have not applied that Java update at this time.

hello thanks for reporting back, please still check in the addons panel if you find anything there that you have not installed on purpose & do a scan of your system with security software to make sure that you're secure.