In my case program FP_TEST_00 helped to get more details about the error. We had this issue because the SID (system ID) was changed few weeks ago and destination for Adobe forms was wrong, there was no destination for a new System ID. New destination...
In this case if you want to add blanks for character type with concatenation just replace ' ' with ` ` and it will works. Example CONCATENATE ` ` ROW_STRING INTO ROW_STRING RESPECTING BLANKS.
