Bluetooth connection fails in BLE app immediately after connection

[guywire]

Using the Disaster Radio BLE app, radio is found, says connected and immediately fails with the message "/storage/emulated/0/osmdroid did not find any map files , using online MAPNIK
App closes immediately.

Note, the instructions to change to bluetooth mode could use some improvement in the readme. I tried to use arduino serial monitor for a long time with no success, but using putty as a terminal while connected to USB allowed the /set ui command to work.

Using Disaster Radio v1.0.0-rc.1 and originally preloaded TTGO ESP32 V2 from Aliexpress.