A Microsoft file hosting and synchronization service.
I'm sharing my experience with the same problem, not that it's particularly useful, but I guess it's more information. I had the same problem and would be redirected to the same "something's not right" error page. This happened for about 2 or 3 weeks I think. Then one day, mysteriously, it allowed me back in. And then when I went to sign in again a few days later, I was not able to get in again. I guess my reason for sharing this is that, if I had my time over again, during that brief window when I was in, I would have downloaded and copied all my OneDrive files to another location, in case I'm no longer ever able to access them again. I hope you all here will have better luck than I've had or at least will be able to access your files temporarily and be able to download them. Sorry I can't be more help. This sucks. Oh, I also changed my password during the time I was able to access the account, just to hopefully add another layer of security in case someone (the administrator of the account?) is able to access my files. I don't know if that helps or anything.