Hello id0, this is Sasuke KANNAZUKI. Call me Sasuke.
Sorry to say, I cannot inspect your problem. Because I don't have YEP Event Spawn and now I have no way to get the plugin.
Both Yep and HookRope are so complicated, I cannot exactly answer where in the plugin invokes error,
I guess it might be because my plugin adds several new properties to the events,
and YEP overwrites the functions.
This kind of conflictions are very hard to solve, especially without inspecting the YEP plugin.
If I had the YEP plugin, I could help you, but this is the limitation of me.
Someone who has both plugins might be able to help you.