Hello, thinBackup developers! Thanks for a great plugin - we've been using it for several months and it's very helpful!

2 cents though.
We've recently started to observe the attached picture. I.e. messages "ERROR", "Not Found. Sorry!The page requested was not found." under the edit boxes.

We are behind the proxy. The global jenkins proxy config (as well as the config for the container) is correct - jenkins receives updates for plugins successfully.