When updating the MAME roms and mame64.exe from 0.211 to 0.212 I noticed that some games would not launch from GameEx Arcade Edition but they were still able to be launched from MAME by pressing tab from a launchable rom and using "select new machine". After many rollbacks and forward, I think that the problem is with the bezel setting. If "don't use bezel' is selected, everything is fine. If "use bezel for vertical games" is selected, vertical games will fail to launch.
Thanks for your attention.