Whilst pushing out a config from the WLSE to numerous AP's, the job for some AP's hangs. If left it could run for hours and you can not stop a running job from the WLSE, other than power cycling the WLSE...
Stop/Retstart the services from the CLI and then you should be able to stop the job. Upgrade to the latest 2.13 if you haven't done already.
With "services status" you get a list of running processes.
I assume your job should be there as well if it is still really running.