The first step to undoing the offending update was to find out what updates it was exactly. After searching some forums I came across a way to see my update history:
- Open synaptic package manager ("sudo synaptic" in the terminal). From the menu bar, click File -> History and you will see all your updates sorted by date.
Unfortunately I had installed about 20 updates today, and I didn't know which one had caused the problem. By searching through each of the packages named in the History list, I was able to downgrade a few at a time until the problem was solved and I had identified the offending update. To do this:
- Use the search bar to find the package you want to downgrade. Once you've found what you're looking for, click on the package to select it. From the menu bar, click Package -> Force Version and select the previous version of the package from the drop down menu. Click the "Apply" button to apply the downgrade.