Blank screen on boot

So the muon install also removed stuff? Normally it shows when something is about to get removed.
It’s really strange and still looks like something with the packages is conflicting on your machine.
Can you run sudo apt-get install -f to see if it fixes something.
If not try to install plasma-desktop. If that is already installed you might be only missing kde-workspace-bin.

No, I wasn’t trying to upgrade when the original problem started. I had rebooted (not after updating or upgrading) because the computer was suddenly slow to load things and Gwenview wouldn’t load at all. Only it wouldn’t reboot properly. I just got a blank screen. It was recommended in this thread that I do the upgrade to fix that, which it did, but after the upgrade Muon and several other things were missing. Then after re-installing Muon and removing Nepomuk (recommended in this thread earlier) I got the error I mentioned above and then the black screen. So, no, I hadn’t tried to upgrade that computer earlier. I do run Netrunner on my desktop as well and upgraded that a week or so ago with no problems. I just hadn’t had time to bother with it on the laptop and it didn’t look like a necessary upgrade.

Thanks for your help guys, but this laptop has been down too long and I need to get it up and running. I’ll either reinstall Netrunner or possibly go back to Solydk. Should I mark this solved?

SolydK is also a nice distro. But since this has not really been solved, lets leave it open this way.

Yes, it is. I like both distros a lot. Still running Netrunner on my main pc though, and it seems very happy there. Thanks again to leszek for spending so much time helping me with this.