I just did a firmware upgrade on my 4 and now it shows signal loss and won't fly. Can anyone help resolve this for me?

It is RC signal loss

looks like its happening to a lot of people including myself also not just the P4 im using P3A and now have the same problem ( have you tried reconnection the rc to the drone?)

i have. have deleted app on phone and changed batteries. since the upgrade the drone when starting up has a different start up tone? Also yellow lights are steady blinking