I haven't fired up MD for a while - the iPad has had several major updates since I last used it - and now it crashes when I try to open the Connect dialog in Config/Connections. This is on an iPad Air 2 running 13.1.3. I press the Connect button and MD immediately closes. The MD version is Pro 2 Version 2.121 Build 191007.
I've been able to use it by running midimttr first and connecting to my BLE device there, then running MD, where it seems to already have the Bluetooth Source and Destination listed, so I don't need to press Connect.
Is the crash a known problem with this iPad OS version?