The CAUSALMED procedure ends abnormally if you specify the REF=FIRST option in the CLASS statement


PROC MCMC terminates abnormally if you specify the REF=FIRST option in the CLASS statement. The following messages are issued to the log:

ERROR: An exception has been encountered.
Please contact technical support and provide them with the following traceback information:
The SAS task name is [CAUSALMED]
ERROR: Read Access Violation CAUSALMED

You can work around the problem by specifying the DESCENDING option instead of the REF=FIRST option.

This has been fixed in SAS® 9.4M8 and later releases.