Hello, I have the same problem in ue4.23. When I press play the engine crash and It gives me this error in that line.
These are null pointer errors in both cases. Look for the line in your code that the crash is mentioning. I will bet there is a variable there that isn’t initialised to anything.
Are you instantiating the C++ version of the character by any chance instead of the blueprint version. Be safe and do a null check in code to avoid the crash even if the character is misconfigured.