I tried to create a line plot graph with variables for Horz, Vert, Group and Group Chart By task roles using the GUI. I have 3 variables for the Group Charts By role, the first of which is STRM. I kept getting the message "ERROR: Data set WORK.SORTTEMPTABLESORTED is not sorted in ascending sequence. The current by-group has STRM = 2082 and the next by-group has STRM = 2064" even though I had sorted the input dataset by the Group Chart By variables.
I copied the code produced by the GUI into an new code window and saw that it was sorting the temp table first by the Group variable before listing the Group Charts By variables. I modified the code to change the sort order so that it sorted first by the Group Chart By variables before the Group variable. When I ran the modified code, it worked as expected, creating a separate chart for each unique combination of the 3 variables, each chart with separte lines for the distinct values in the Group variable.