rronaldson replied to the topic Leica M240 hangs/freezes on startup after updating to 2.1.0 from 2.0.6 in the forum Leica M (Typ 240) 4 months, 4 weeks ago
Have you tried resetting the camera? It's an option in the menu.
I bought a used M 240 just before Christmas. I updated the firmware to the latest today and suddenly all my exposures were underexposed. I checked the settings and found that the exposure compensation had been set to the negative end of the scale. Reset that to switch exposure compensation off and exposures are now correct.