Been running a GroovyArcade Linux for 3 years and decided to try the Windows version

Otherwise doing just fine, but as I start GM, I get the following error:
"[LUA ERROR]plugins\boot.lua:19: attempt to index a nil value: (global "mame manager") If I click ok, GM starts.
Any clues what this is all about?
WinXp64 (all updates)
X300
EmuDriver 6.5
Latest GroovyMame (mame 173b)