You can eventually experience connectivity problems between EXT 200 LED and MUM if you are having a version of the DABS1 interface lower than 1.2. As the interface firmware cannot be updated, only solution is to replace the interface with another one holding at least version 1.2 of the firmware.

The firmware version of the DABS1 interface can be seen in the MUM application by connecting the interface to your PC (no fixture connected):