Yesterday, I was preparing to run an app that has worked perfectly for weeks when I accidentally pushed the debug button instead of the run button. While before I had 0 errors now I have over 20. All of them have to do with not resolving the R class anymore.
I have combed stackoverflow and tried many of the "fixes" but to no avail. I have tried cleaning, rebuilding, syncing, manually importing then rebuilding etc etc. Most of those fixes come from last year anyway. I am using version 0.5.2. I am new to Android development and Android studio (and stackoverflow for that matter) so I apologize if this question is trivial or has been answered before.
Solved:
There was an undisclosed error in a string resource.
...is roughly equivalent to my mistake.