This is not related to nvidia or bumblebee. I'm having same error when trying to modprobe nouveau:
# sudo modprobe nouveau
modprobe: ERROR: ../libkmod/libkmod-module.c:816 kmod_module_insert_module() could not find module by name='off'
modprobe: ERROR: could not insert 'off': Function not implemented
This is not related to nvidia or bumblebee. I'm having same error when trying to modprobe nouveau: libkmod- module. c:816 kmod_module_ insert_ module( ) could not find module by name='off'
# sudo modprobe nouveau
modprobe: ERROR: ../libkmod/
modprobe: ERROR: could not insert 'off': Function not implemented