Okay, I fixed the issue with mate-applets. Let me know if you get a chance to test the upgrade from 1.12 to 1.14 again. Thanks!
YES! YOU DID IT !
A generic, well-working Mate 1.12 upgrades to 1.14 from [antergos-staging] without a hitch now.
No tricks, no tweaks are needed, just follow the instructions given in the OP.
The upgrade is smooth, painless, boring. There’s nothing to say about it. The full terminal output is in Pastebin here.
It worked exactly the same way on two other computers with Matte 1.12.
At this point I can’t be of any help, I’m afraid, as everything works very well here. Can’t find other problems.
Well done, Dustin! Much appreciated. Thank you!
With max respect