LEICA posted this advisory regarding the issue that the Leica SL3 may sometimes encounter when changing the battery:
Unfortunately, with the current firmware of the Leica SL3, there have been isolated cases of previously saved images being overwritten unnoticed. As the error can occur if the camera has not been switched off properly (e.g. when changing the battery in standby mode or after an unexpected software interruption), we strongly recommend careful handling of the camera in accordance with the user manual. In such case, we recommend that you save the images immediately to an external device and change the memory card before you start the camera again. Please ensure that you always switch off the Leica SL3 completely before changing the battery in order to minimize the risk of data loss.
We are concentrating with the highest priority on restoring the perfect functionality and usual reliability of your Leica SL3 as quickly as possible. To this end, we are working at full speed with our development team to provide you with a firmware update.
Kind regards
Leica Camera AG
