Never had such warning (Warning: selected invalid function), however.
I guess some things work with some PCs and not with others. Yesterday I installed Rollback RX Hone freeware. It is limited to 7 snapshots but you can go forward as well as back. Also you can consolidate the snapshots into a new baseline, and thereby have 6 to use as you like. It seems to work ok. And it is still being developed. Also the support forum is active. I posted a question today and got a reply already.http://www.horizonda...roductId=40#Features
The Pro version is supposed to have unlimited snapshots. If I see it on a giveaway I may try it out. But 7 snapshots may be enough to act as a replacement for System Restore. Also I have images with Macrium Reflect in case something goes sour and I can't boot or some other problem.
The only real drain on the system is evident during bootup. Once on the desktop applications all run normally. I tried a restore as a test and it restored the snapshot in about the same time as a restore point would use.
Thanks for your reply.