Online IDE Error Message.

Online IDE working well on my MacBook Air and MacBook Pro. But out of nowhere I started getting this on my iMac:

400 Bad Request

Request Header Or Cookie Too Large
nginx/1.10.3 (Ubuntu)

I can't seem to get around it! Works and loads up fine on all of my other Apple products, even my iPad, but just suddenly started with the above error on my iMac. - Help!

Did you upgrade anything on the defective computer ?
It would seem Catalina has caused all sorts of issues.

I have the same problem. I worked the past few day an my laptop with Windows 10, didn't make any updates and out of nowhere the side started to refresh itself every few seconds. A few moments I was in the Editor than I was kicked out.
Now came the

400 Bad Request
Request Header Or Cookie Too Large
nginx/1.10.3 (Ubuntu)

-Problem. The same situation is on my iPad.

Has anyone an idea what the problem might be?