Leica released a new “dummy” firmware update 2.0.0.12 for the M type 240 rangefinder, but you don’t have to really upgrade if you already have version 2.0.0.11:
All new cameras being produced now have a new firmware version 2.0.0.12 installed on. An update for already delivered cameras with version 2.0.0.11 is not necessary, as the changes implemented only apply to the internal production processes. On the application level, no difference between 2.0.0.11 and 2.0.0.12 can be recognized. Nevertheless, we provide version 2.0.0.12 through our website, because every camera is compatible with Version 2.0.0.12 . We do not recommend to “downgrade” from 2.0.0.12 to 2.0.0.11, because unexpected behavior could occur.