Is there a error message showing anything? Can you post a screenshot showing the issue? What security software are you running? What version of Firefox? Have you tried running Firefox in Safe Mode? https://support.mozilla.org/en-US/kb/diagnose-firefox-issues-using-troubleshoot-mode#search

I just get a pop-up message saying I'm not connected to the internet. Not one thing that proceeds it, can happen at any time. I use McAfee security, but have the same issue if I disable it. Have unistalled, and reinstalled Firefox. Have version 100.0 64-bit. Network adapter is up to date and working properly. I get the following message in Windows diagnostics ....... "Ethernet" doesn't have a valid IP configuration Not fixed Reset the "Ethernet" adapter Failed Investigate router or broadband modem issues Failed The default gateway is not available Not fixed Investigate router or broadband modem issues Failed Reset the "Ethernet" adapter Completed

I would run Windows in Safe Mode with networking. Windows Safe Mode: How do I start w10 in Safe Mode? Press Windows key + R (force Windows to start into safe mode every time you reboot the PC).

   Press the Windows Key + R.
   Type msconfig in the dialog box.
   Select the Boot tab.
   Select the Safe Boot option and click Apply.
   Choose Restart to apply the changes when the System Configuration window pops up.

I will try that later. Thanks.