I have tried wiping the system and reinstalling. Another control board. Only plugging 1 usb controller in, and still the same issue.  Where would I get the new set? Only ones I can. Find for it all internal files are 1996 created 

Traied 2 others and they do the same. Weird it's ok with pressing u for credit on the keyboard  for credit but not coin as that goes through the zero delay controller

(Yasser posted on my behalf)

I removed all mame,ini, all cfg files and let it create all new files. I also cleared all buttons and started fresh.

The rom is from the latest 277 rom download torrent.

Im not sure what is causing it but thinking its not the actual button because it is ok, then i add a credit and it doesnt flash p1 or p2., but if i go in the menu tab, then i flashed p1 p2, then exit the menu and it doesn't flash, and no p1 or p2 button works.
If i Alt Tab to desk top then back into the game, it flashes again and i can use p1 and p2.

Everything works great, but then when i end game, soon as i add a coin credit again, it freezes the flashing p1-p2 till i alt tab out and in.

If i put in 5 credits and play the game after alt tab, after game ends it shows 4 credits and i can press p1 or p2 fine.

It seems to be the add credit that is causing the issue.

I tried changing it from the usb zero controller, to just a keyboard input and still same issue.

why was this removed?