Echoing 3-D-C with praise for Smith Micro. My case worker (John) stayed with me all the way to solution, answering each time within minutes. This may be the best software support ever. The problem does indeed trace to a LavaSoft dll, which is not easy to root out in Windows 10, but once you deal with it you're fine. I want to add thanks to those who posted here. Nice to have smart people around when you need them.