Kyle,
thank you for explaining what is going on. I have been struggling to understand "cause & effect" here & your explanation of the code line 782 helps me.
1) CB Auto actions were not extended. But I disabled the plugin to check.. . not the problem.
2) Your excellent troubleshooting tip helped me locate the cause

. . .
the error msg disappears when I disable the CB Menu plugin.
QUESTION:
The CB Menu plugin version is current; should I uninstall & re-install the same plugin?
NOTE: I went to CB Tools & ran a "check CB plugins database" - the resulting msg read "
All CB plugin "CB Menu" database is up to date"