symbol's function definition is void: button-lock-parent-modes

[nixin72]

When trying to enable global-fixmee-mode, an error is thrown stating the the function button-lock-parent-modes's definition is void. When looking at button-lock.el that was downloaded from MELPA, I can find the function button-lock-parent-modes, but I'm not sure why global-fixmee-mode throws an error saying it can't find it.

In addition, this error thrown isn't handled properly, and Emacs refuses to run any commands after that error is triggered. Using M-x simply repeats the same Symbol's function definition is void: button-lock-parent-modes error back at me whenever I try using it after calling global-fixmee-mode.

To fix this, I just removed the line 938:

(not (intersection (button-lock-parent-modes) fixmee-exclude-modes))

While this seems to have fixed the problem, I don't know what other consequences it may have, but regardless it appears to be working for me.