Three days ago, I installed a mac update and after restarting -- it wouldn't boot. Essentially, it bricked the machine. This is a 2015 imac. I ended up erasing and reinstalling. After getting everything setup again, I put Malwarebytes back on. As soon as I rebooted, it bricked (and by bricked, I mean, I freezed on the boot screen...if I restart again, it gets to 100 percent, and then just shuts off). I'm not sure what happened or how I can get you information that would be helpful, but after erasing and reinstalling again -- I've not reinstalled malwarebytes and everything is working fine.
I don't know what was in the last update, but something with the the software caused an issue on my end.
--tr