The imqusermgr command displays the following message to the console:
To reproduce, download GlassFish (e.g. build glassfish-4.0-b80-03_13_2013), open a command window and navigate to the glassfish4/mq/bin directory. Then type imqusermgr with no parameters. This command works as required (it simply displays the command syntax) but also displays the warning message above.
This may be a Windows-specific issue which does not occur on Solaris.