Logon Loops

I sat up some tasks and then later logged in only for the system to loop me back to the home page. Landing page panel attempts to load but will not. I log out, log in, looped. Reopen Firefox Developer 72.0b11 browser try again, looped. Clear cache, try again, looped. We can't use the system where it doesn't allow dependable access. Earlier, I tried to change the initials to a company logo and it will not change, no matter how many different ways I loaded the 45kb JPG, the system refused to allow a logo to be inserted.