@FuriousRelic3
Before ditching the 'gameconfig.xml' you have installed, open it & try resetting the 'MISSION' stack to default (20500) like below first (it may work ):

<Item> <StackName>MISSION</StackName> <SizeOfStack value="20500"/> <NumberOfStacksOfThisSize value="1"/> </Item>

If not, then follow @Pizzahut's advice & try a new one.