Error waiting for the window "ahk_class MAME" to be come active

[stampedem]

This error has recently started to come up when I try to start a game. Specifically, I'm trying to set up my Atari 5600 wheel in hyperspin. I'm using MAME/MESS emulator. RetroArch seems to be a complete failure anytime I try to set it up with an Atari System, and MAME throws me into a black screen of death. MAME/MESS emulator starts the loading process, and get's me to 100% loaded. But then it hangs and gives me an "Error waiting for the window "ahk_class MAME" to be come active" message.

Can anyone offer any guidance or insight? Thank you for your help. A Google search suggests that this problem has existed with other persons, but no clear solution seems to have been articulated.