Experiment won't open- Unhandled internal error

Builder
1

Hi, I encountered this error seemingly out of nowhere and can’t figure out what the issue is. I’m super new to Psychopy and programming in general so any help would be super appreciated.

Traceback (most recent call last):
File “/Applications/PsychoPy 2.app/Contents/Resources/lib/python3.10/psychopy/app/builder/builder.py”, line 1038, in OnFileHistory
File “/Applications/PsychoPy 2.app/Contents/Resources/lib/python3.10/psychopy/app/builder/builder.py”, line 800, in fileOpen
File “/Applications/PsychoPy 2.app/Contents/Resources/lib/python3.10/psychopy/app/builder/builder.py”, line 1126, in updateAllViews
File “/Applications/PsychoPy 2.app/Contents/Resources/lib/python3.10/psychopy/app/builder/builder.py”, line 4187, in draw
KeyError: ‘term’

OS: macOS 15.6.1
PsychoPy version: 2026.1.3

2

Looks like the app is struggling to find the terminator (term) for one of the loops - could you share the .psyexp file?

3

Here’s a solved thread with key error “term” where routines needed to be renamed.