Can't change jump height in a 2D sidescroller

I’m trying to make a power up that changes character jump height. The blueprint for it is being scripted in the character blueprint itself (not sure if that is what’s giving me the error or not, just thought it was worth mentioning)

When I run the game and collect the power up, I get this error message:

This is how my blueprint is set up:

The way it’s supposed to work, is when the character collides with the powerup, the character destroys the power up, and then gets a jump boost. But for some reason the game crashes when I run into the jump boost powerup and i’m not sure why. I have this same exact setup with a different powerup, but it changes the Walk speed instead, and it works flawlessly.
Any ideas?

UPDATE: I just realized I can click the links in the error message. If I click the link for the node receiving the error, it highlights the “SET” node right after the Set Timer by Function Name node. I’m a noob at this so I’m not too sure what that means, but any help would be appreciated.