Begin play nodes were removed from a number of blueprints to make it easier to integrate other assets and make it easier to possess SGK characters.
Add the highlighted nodes in the images below, locations at the tops of the screenshots. You will need to new custom events for these images.
Next go to the BP_MasterCharacter and create a new custom event called Client Possessed set it to Run On Owning Client and tick reliable. Then copy the images below.
Then copy the image below, location at the top of the screenshot.