What link are you using to sign in? Try a different one to see if that makes any difference.
Some users seem to be getting a similar error, but only when listing or editing images. Others are not getting that error at all, though.
Are you using a VPN? If so, that might be causing an issue for you.
Some other things to look at here:
https://community.ebay.com/t5/Report-eBay-Technical-Issues/30-Days-of-listing-I-get-quot-Where-s-all...
