Mmm the problem is that all the Msys packages I get have an older GCC, making messui to fail, or the GCC 10.2, making messui not to boot.
Tried updating the package manually and with pacman, but no way.
If you have the msys64 for windows with that GCC version and you can send me it, I could try to compile again messui from 227 to 229. Otherwise I won't compile until it gets working with the current 10.2.0. No problem since the mess only works.