Have had no issues until now.  Fly even yesterday writh no issues, tried today and it will on connect, tied several time removing reconnecting, turn on and off bird and controller with no luck.  I am still new to all of this,  Hel p please!

check the pins in the connector on underside of bird. if one or more is bent it will not connect

May I know if there is any error message in the APP? please try TruGreen's suggestion to check the PIN to see if they are tidy and clean.

I might add to check the ribbon cable.  Between the craft and gimbal there are two ribbon cables.  You might have come loose, but hard to say.  Look at this video and you will see the two cables and how they connect to the gimbal.  When the craft starts up (when you power on the battery) does the camera go thru the spinning motions?  Do you at any time on you mobile device have a picture?  Last thought, uninstall the Go App, and reinstall.  Just a few thoughts here, so let us know the outcome.

Most would not put a X3 on an I2

Are you talking I1 or I2 ?

My DJI ronin sc is not communicating with my camera nikon z 50 , why? Also it's hard to insert micro usb cable to my camera that came with Ronin sc gimbal