The beta requires JLP support. The same ROM shipped in the beta starts on my Windows jzIntv setup with JLP enabled using -J1. If jzIntvGUI exposes a JLP setting, try enabling it and launching the extracted TerraPrix.rom again.. If it persists, could you share your jzIntvGUI version, the TerraPrix build you downloaded, and whether the app has a JLP option? That would help me narrow down where startup is failing.