For a few days now, I've received an error message whenever attempting to update the Main OSS Repository.

I have tried to contact someone within the community with this information, but (probably because of my own ignorance how to do it the right way) failed.

This is turning into a major headache, since it seems to have propagated to the mirrors as well.

The message says

Download failed:
Curl error for ''
Error code: HTTP response: 403
Error message: The requested URL returned error: 403