If you are trying to work with the LRx4 and LRx5 Radar DTM and you are locked into one type of radar, you can change the radar model. This 3-minute video shows you how.
For example, the DTM reverts to LR74 when I start it up. Now I can select any one of the five models of radar to demonstrate the DTM or configure a selected model offline. It's worth mentioning that you have more connectivity and options when you are actually connected to an actual radar...but you *can* get some experience even in offline mode (not connected to an actual radar) using DTM as a standalone.