Hello, I am having a similar problem to ardeniosilvenes. I have the exact same error message popping up when I try to upload something into my assets. I tried to re-load, upload to a different folder, upload a different file, log out and log back in, went to safe mode, and uploaded directly into the asset folder, all of these did not work, and I’m not quite sure what’s going on. Help would be very appreciated.
So I have no idea why, but it started working??? Either way, it’s fixed.
Another user reported a similar issue and I’ve just finished debugging the problem, for some reason, it appears uploads were being sent to the wrong server. We changed things on our side to work around the problem, though we don’t know why the browser was sending requests to the wrong servers 
Do you use Firefox by any chance ?
Either way, the problem has been fixed now!
Thanks!
I do use Firefox. That’s weird. I’m just glad it’s fixed. Thanks for the reply anyway!