Warning: This topic does not affect the C generator.
If the execution of your program is interrupted by the "Unit or session Error", check the value of WRAN0n.
It cannot be less or equal to zero, and it cannot be greater than the number of records written in the subfile.
Check also that there is no field whose value is incorrect when the format to which it belongs is defined. It may be a numeric field - a DS subfile - containing blank positions.