Under Linux, if you attempt to call BluetoothLowEnergy.registerProfile when the nRF52840 dongle isn't connected, the simulator crashes with no explanation. Now obviously without the dongle connected you're not going to be doing any useful BLE development anyway, but it's not a very obvious failure mode. It would be better to throw a BluetoothLowEnergy.ProfileRegistrationException or at the least print a console message indicative of the reason. Sometimes (but not always) I get a cryptic "Socket Error in packet header 0" in the console. In the absence of symbols it's probably of limited use, but here's a GDB backtrace of the simulator: https://pastebin.com/8smyM8fb
I'm using version 8.2.1 of the SDK.
