Hi, im new to UE4 and was following the endless runner tutorial, i decided to add a custom obstacle using the same method as other obstacles and this happens
-HD’s answer is very likely the right answer. The same thing was happening where the “Add Component” button was disabled for me in my new Pawn BP class that I had just added. Switching back to the game viewport and stopping the running game made it so that the “Add Component” button was correctly enabled.