Looks like even the latest Smart Minify version still suffers from an incompatibility with latest MinifyEverything - the former won't show any items on the options screen.

Tried deleting both and re-downloading, deleting config file, to no avail.
The only thing that works is reverting to the older MinifyEverything version:

https://github.com/erdelf/MinifyEverything/tree/f6103740b70c484bcaf8538450106b5dc7697c32/1.5/Assemblies

Unsure if this was maybe fixed in 1.6, but being on 1.5 the issue is very much alive.