Try this! It may help.
The reason for your runtime error is probably if you try to punch or otherwise attack before an enemy is found to target. It’s saying “I want to do the punch code, but there isn’t an enemy!”
The way you get around this is right after your attack event, first thing you should check is “?IsValid” with Target Enemy plugged in. Then if it is not valid tell it to do nothing, if it IS valid do the rest of the code.