Rg350m 64gb card issue

[Nightking2020]

Just got my new machine really happy..butttttt
When i attempt to load a game from the mame emulator ..nothing happens when i press A
the game list is in redish orange and nothing seems to work..do i have to do something else?
Any help will be most welcome im a newbee

 

[admin]

Can you please plug micro SD into your PC and check if the files in the MAME folder are accessible?