The following error message might be issued when you use PROC MEANS or PROC SUMMARY with a CLASS statement that includes many variables:
ERROR: Utility file open failed.
To circumvent the problem, include the NWAY option in the PROC MEANS or PROC SUMMARY statement.
Without the NWAY option, the procedure tries to create all possible _TYPE_ combinations, which is 2^n. In the process, the procedure runs out of memory and the current summary object tries to open one file for each _TYPE_ being created. This results in the error message above.
Other circumventions include adding the NOTHREADS option to the PROC MEANS or PROC SUMMARY statement and/or using a BY statement instead of a CLASS statement.