Question one have you tried the above example in a empty template to see if your code is working and do it piece by piece.
Question two. If you are using a debugger did you pull the debug menu away from the game screen. This has known to be double the resource drawn on one cpu core and not allowing multiple core to work.
Question three. Have you look at tutorial on saving and loading and recreating them step by step on a blank template.
If you said yes to all then You must have something going on in your other event that are pre firing infinitely because of some previous condition wasnt exactly ready but at the same time where your progress is at it maybe refiring them all at the same time.
this is all i can do to help you without us taking a look at your project events. its like trying to fix a car through a phone. do you know how hard that is ?