Please ensure the Analysis code being used is correctly set up. Exchange difference default analysis codes are set up on the currency record. These can be checked using the following steps:
Select System, Currencies (ribbon menu) or System Control, Currency, Trading Currencies (classic/module menu)
Select the relevant currency record,
Check the analysis code listed in the S/L Exch Diff and P/L Exch Diff fields
If you need to edit these, select Edit
Update the analysis code as needed (note that you can remove the analysis code from the field and select the Tab key on your keyboard to show the analysis code search screen).
Once you have completed your changes select Save