If I try to refresh the Update manager, I get an error message for Skype. See post image link.(I should've c+p'd this from Terminal, so sorry about that.) I've tried one solution suggested online to delete the signature key but it didn't work.
https://i.postimg.cc/Qx3yrdbH/skype-puzzle1.png
Ideas?
Bev. (Cinnamon 19.1.)