Just bought this. The game played the intro, faded to a black screen and resetted itself (it did this on a loop 4-5 times). Then displayed the same error message other users were getting.
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FATAL ERROR in
action number 1
of Step Event0
for object oClient:
Unable to find any instance for object index '100012'
at gml_Object_oClient_Step_0
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stack frame is
gml_Object_oClient_Step_0 (line -1)