Error when emptying trash

Every time I empty the Trash folder I get an error saying I can’t delete a special folder. I am on Win10 with em client version 9.0.1708. The email disappears and the Trash folder remains as it should, but this error message is really annoying. It started happening yesterday.

I have also noticed a long list of alerts popping up. Was there a change to the code or the communication with yahoo? It does not seem to be affecting my gmail accounts.