I'm running MacOS High Sierra.

I've deleted RoboFont, all .py, preferences and Mechanic master extensions. I've restarted my machine. Robofont 3.0 and beyond open, but give me this error when I try to open a new or previous UFO:

**A problem occurred when trying to open this UFO.**
Traceback (most recent call last):
  File "lib/doodleDocument.pyc", line 276, in makeWindowControllers
  File "lib/doodleFontWindow.pyc", line 66, in __init__
  File "lib/UI/fontOverView/__init__.pyc", line 244, in __init__
  File "lib/UI/fontOverView/smartSetList.pyc", line 1064, in __init__
  File "lib/UI/fontOverView/smartSetList.pyc", line 935, in __init__
ValueError: NSInvalidArgumentException - Unable to parse the format string "Name CONTAINS……… (then lists a character set)…

Pre-3.0, RoboFont simply crashes.

I've tried loading multiple versions in SafeMode without success. I've tried opening UFO's with Single Window mode checked and unchecked.

Is there anything else I can try to fix the bug?

Somehow you managed to add a Smart Set in which the search query is not valid.

You can use a script to remove a single item from the Smart Sets list, or completely remove all Smart Sets.

Run one of these in a Scripting Window:

1. Remove all Smart Sets

# be careful: this is not undoable
from mojo.UI import setDefault

setDefault("smartSets", [])

2. Remove a Smart Set item

from mojo.UI import getDefault

# get all Smart Sets
smartSets = getDefault("smartSets", [])
# print out Smart Set names with index
for index, smartSet in enumerate(smartSets):
    print(index, smartSet["smartSetName"], smartSet.get("query"))

# set an index number, and uncomment the lines below
# indexToRemove = 3
# del smartSets[indexToRemove]
# setDefault("smartSets", smartSets)

good luck!