panagiotismavridis/NTUA-ECE193P-Exercise-1 — comment on commit 9bbf6b1d53427ca386e9c06b4a9afe083ad8b2be
File: calculator/Calculator/en.lproj/MainStoryboard.storyboard line 0
By andreasnomikos:

if you check this file on IB the view outlet of the Calculator View Controller is pointing to the "backspace" button causing an error.