When running an import into GL Transactions, the currency ID is not defaulting. The currency is mapped, and I have it setup as the functional currency.
The issue can be resolved by making sure there is a checkbook ID in the company that has a currency ID associated to it or an item associated to a currency ID. Another place to check is to ensure that the functional currency index value in company database (MC40000) matches the currency index value in Dynamics Database (MC40200).