Internal Error. Bad parameter - when opening messages

hello Everyone:

I have a user that is getting this message "Internal Error. Bad parameter" when opening some messages

1. GW Client version: 8.0.3
2. Executed GW Check (Analyze/Fix Structure/Index) and (Analyze/Fix Structure/Index/Contents) everything checked okay (no errors)

Please, share any ideas you may have

Much appreciated, thank you