What update are you trying to apply? What error are you getting? What version of Mac OS X?
Mac OS Yosemite 10.10.5
The new error is U44M2P7
How has it been installed? From the orignal installer (which is correct) or from backup/migration/other computer/other disk (which will not work)?
You could do following:
- Restart the computer and after starting again hold down COMMAND+R, it will let run the computer from the repair partition.
- Run the Disk Utility twice, once for repairing the disk, once for repairing the permissions. It will show you in red errors on your computer. Even if this is not the causing problem, it should be done on a regular base.
- At the end install the System again, it will make a repair installation, because during work some components might get corrupted. This will reset many settings and probably will speed up the computer.
I would expect that you could install it now, or uninstall it at least and install CS6 without problems.