Using the following MODIFY command to define a new facilit :
TSS MODIFY FACILITY(USER10=NAME=NEWFAC)
The following messages are generated:
TSS9186E The Facility name is invalid no such facility name.
TSS0301I MODIFY FUNCTION FAILED, RETURN CODE = 8
Release : 16.0
Component : CA Top Secret for z/OS
The facility USER10 is already used by another facility
Check the user defined facilities in the Top Secret parameter file in the PARMFILE DD in the Top Secret started task and select an USERxx facility not currently in use.
There is more information about the USER FACILITIES at the following link:
USER FACILITIES