My fettec FC will say connected but I cant use any features.

Hello,
Does anyone know why I can connect to the firmware but not use any features anymore. I was previously able to but now it will only stay connected.

[lichtl]

Do you have some more details for me? GUI version, OS version. Does the FC still work (what is the status of the LEDs). Any change when you short press the BL button and connect?