After a long time with no MAME using, I got 0.178 and all the ROMS and CHDs and very happy for MAMEWUI have been merged with the project.
Anyway, with all settings ready, when I start the executable I get only a black screen showing "Initializing" and games don't load... I was considering the size of the pack and waited for HOURS (when I went to bed I left it running hoping by the morning it'd be at that list on the screen at least), but nothing happened... the "initializing" was still there and I couldn't close the window at all, even through Task Manager, so I have to reboot my system... Did that several times and the problem persists...
I'm running it from a external drive but was sure that all the paths were OK, I rechecked them and they look fine to me. Doing some research I thought it was something related to DirectX but my version is up to date. I'm using Win10 x64 and MAME64.