"Sorry, Ubuntu 12.04 has experienced an internal error" "If you notice further problems, try restarting the computer." "ExecutablePath /usr/lib/update-notifier/apt_check.py"
I've restarted the computer before, and it didn't resolve it.
Another popup says "Invalid problem report"
"Could not determine the package or source package name."
I remember I did something in the terminal where I did something to get automatic updates or something like that because I would have this problem where it would always tell me that there were updates and that I should start the package manager, but starting the package manager would only take me to the homepage of the software center. I'm not sure if that had anything to do with it, but the problems started after I did that.