I sometimes have a problem connecting to a URL. It does not make any difference which URL. Microsoft Edge has the same problem when this occurs. I have two network connections. One is via Ethernet and one via WiFi. I generally don't connect the WiFi since I am sitting next to my router. Yesterday, when this occurred, I connected the WiFi and everything worked. I thought it had something to do with my WiFi, but today when it failed I tried the same thing and the problem continued. I ran the Microsoft troubleshooter and it displayed that I was connected to the Internet. When this occurs I can ping my router successfully, but I cannot connect to my router via Firefox or Microsoft Edge. Today I rebooted my router, even though other devices do not have a problem connecting to the Internet, and when the boot was completed everything worked. When I rebooted the router my PC indicated that it did not have a connection and when it was able to access the router initially it indicated that I did not have a connection to the Internet. When my PC indicated it had an Internet connection Firefox functioned correctly. I have a UPS which has my router, modem, and desktop PC connected. We have had power failures and either my PC is turned off or I turn it off. My router and modem continue to function and we can access the internet via tablets or cell phones. I was wondering if the power failure somehow could have affected my network provider and I needed to reset my router so that it could establish a new connection to the modem. Don't know if this makes any sense or not. I have Microsoft Office 2021 which is Microsoft's perpetual license version of Office 365. I use Outlook in Microsoft Office 2021. What surprised me is that when this is going on Outlook will function correctly. Is there anything I can access in Firefox that can help me determine what is going on, or do you have any suggestions?