There seems to be a turf war between two parts of my Mac.
On the one hand is Disk Utility, the app that allows you to manage the disks on your Mac, whether it’s formatting new ones, or carrying out maintenance. One thing that Mac users are encouraged to do every now and again is use Disk Utility to Repair Disk Permissions, to ensure that the system files that make up the OS X operating system are correct. Sometimes the file permissions can end up being changed, preventing apps from running correctly, so if your Mac is acting weirdly repairing disk permissions is a good first step to take to try.
On the other hand are the drivers for my HP Printer, which also require its files to have certain permissions to work. And evidently, these are not the same permissions that Disk Utility thinks it should have.
What this means is that every time I run Disk Utility to repair disk permissions, it changes the file permissions on my printer drivers. So the next time I want to print something, the drivers complain that their permissions are incorrect and offer to correct themselves, which takes a couple of minutes. Thankfully, repairing disk permissions isn’t something I have to do regularly, and nor do I print things very often either, but it’s inconsistent and a bit frustrating.
What’s more odd is that the drivers for printers are now provided via Apple and not direct from HP, so you’d think that Apple would have noticed a problem like this and ensured that it doesn’t happen.
As for why I was repairing disk permissions: for some reason, Time Machine hasn’t been able to complete a backup for over two weeks now. It gets so far and then seems to get stuck. Alas, repairing the disk and permissions on both my internal and backup hard drives didn’t seem to fix it so I’ll need to look into it further.