A Parallels Plesk Automation (Plesk) upgrade from 11.0 to 11.5 fails due to lack of memory. From poaupdate.log:
/var/cache/ppa/dists/PPA_11.5.0/POA/./os/RHEL/5/packages/sc-RHEL-5-i386-ProFTPD-188.8.131.52 ERROR [addPackageMass] system exception, ID 'IDL:omg.org/CORBA/COMM_FAILURE:1.0' TAO exception, minor code = c (failed to recv request response; ENOMEM), completed =MAYBE ERROR at doMassImport (/var/cache/ppa/dists/PPA_11.5.0/POA/poaupdater/uPackaging.py :461) in raise Exception('ppm ctl exited with code %d: %s' % (status, "\n".join(errlines))) at fn (/var/cache/ppa/dists/PPA_11.5.0/POA/poaupdater/uAction.py :118) in return fun(*args, **kwds)
The upgrade requires more that 4 GB of memory for upgrade. If you have 4 GB, it may fail with the error above.
Upgrade memory to a value higher value than 4 GB (example, 8 GB) on the Management Node and try to upgrade again. If it continues to fail with an error, please contact the Parallels Support Team.