Error while trying to download (code: ): https://getgrav.org/blog.atom

After almost a month of running with minimal issues the Grav site now suddenly shows this in the Admin GUI.

Error while trying to download (code: ): https://getgrav.org/blog.atom

Any ideas?

Same problem…
Error while trying to download (code: ): https://getgrav.org/blog.atom

Any news?
Suddenly it has appeared on mine two web sites