I am continually having this error 'Failed: Another installation is currently in process' when trying to deploy packages using the push method. Even if there are no installations running concurrently the scheduled task will fail with this error. I will sometimes try to end tasks of msiexec.exe, vulscan.exe or sdclient and yet this won't fix the problem when rerunning the task. I will have to restart the machine. This happens on most of the cases.