You have customized the WebSphere MQ (WMQ) MCAUSER attribute to the userid "mqm" in the system objects SYSTEM.DEF.SVRCONN and SYSTEM.AUTO.SVRCONN.
You run the command "strmqm -c".
You notice that these system objects have a blank value for MCAUSER.
Resolving the problem
The MQ system command "strmqm -c" replaces all existing system objects and resets any customizations to these objects. It actually deletes the system objects and recreates them with their default configuration.
Therefore, you will need to recreate the customizations that you may have done to the system objects.
Before executing "strmqm -c" you may want to backup the queue manager:
a) If using MQ 6.0 or 7.0:
You can use the following SupportPac™:
MS03: WebSphere MQ - Save Queue Manager object definitions using PCFs
This SupportPac interrogates the attributes of all the objects defined to a queue manager (either local or remote) and saves them to a file.
b) The dmpmqcfg tool is new in MQ 7.1 and it is an alternative to the SupportPac MS03 (saveqmgr).
Here are the main references from the MQ 7.1 Information Center.
WebSphere MQ > Reference > Administration reference > WebSphere MQ control commands > The control commands
WebSphere MQ > Configuring > Availability, recovery and restart > Backing up and restoring WebSphere MQ queue manager data
Backing up queue manager configuration
WMQ WebSphere MQ