Since the following message prevents output from being generated in SAS 9.4, it has been changed into an ERROR message. Prior to SAS 9.4, it was a WARNING message.
Here is the message that you see in SAS 9.4:
Here is the message that you see in SAS® 9.1.3, SAS® 9.2, and SAS® 9.3:
In SAS 9.4, if you code the SAS System Option ERRORABEND, you get a U999 abend and the above error message for SAS 9.4.