Edit: Last night, I used the "Fix MergeList problems" option in the maintenance tab of software sources and at least for now, it seems to be working. So I probably wont need help with this anymore, hopefully.
Every hour or two, the Update Manager keeps giving me an error message saying that my APT configuration is corrupt and that I should switch to another Linux Mint mirror. It usually goes away when I do a manual refresh but it just keeps coming back. I have also tried switching to a different mirror but I get the same error. It also tells me to run apt-get update but even if I add "sudo" it just gives me an error message saying to run apt-get update.
It happened again so I'm adding screenshots in case they help. The first is the initial error, then it's the error I get when I try to change the repository and the third is the error I get when I try running the command it suggested:
Yea that's it. I couldn't remember what the options were and I was going to sleep. I'm back online and if you give me a few minutes I can do my best to help. Clear all the options you can and try running sudo apt get update. Sometimes where there's an input output error it can also be a hardware issue such as a bad block on the drive preventing anything from writing to that block. Go to disks. Find your main drive and repair it, then check it the option above repair. After those two repeat the remove dependencies and duplicate/foreign packages. Finally sudo update. See it that helps.
I might try that later if the issue comes back up. Last night, I used the "Fix MergeList problems" option in the maintenance tab of software sources and that seems to have fixed it. I did at the time think it was an issue with my HDD but disks wont let me check the filesystem because it can't unmount a filesystem that is in use.
Boot up from a USB drive that's what I did. I was just about to add the merge list in the update manager as well. Keep me posted if it didn't work. Best of luck.