Application Crashes when clicking UI elements (checkboxes, buttons, etc.)

The application crashes semi-regularly (not 100% of the time) when attemplting to click on a UI element - a checkbox for staging files, the 'Commit' button, etc. This started on July 10, 2017, but the exact same app was rock solid under daily use prior to that date. There were no system changes in the week prior, all other apps have remained stable.

I've done a clean-reinstall, wiped my preferences, even tried the most recent beta - all seem to crash when a UI element is clicked.