Quoted from ibuypinballs:
I took a Captain Fantastic in on trade that was restored with a playfield protector on it. Looked great and the game played very well. Sold the machine the following week to someone who purchased it for their 1st machine. After three week one of the pop bumpers locked on and fried the pop coil. He changed the coil and it happen again. Being he is 200 miles away I tried to guide him thru checking the pop switch and the relay for that pop bumper. He was intimidated with trying so I had someone do a service call. Turns out the plastic playfield protector somehow caught the pop skirt in the down position causing the pop to stay locked on. I never installed one so I not sure why it happened. Other wise I like the look of it and the machine played very well.
I have had this happen on my Firepower. I was lucky because I was running one of those fuse boards that protects the coils and boards, but it still blew the fuses.
I was able to stop this by taking some fine grit sand paper and rubbing it on the edge of the pop bumper skirt. I can’t tell why it only happens on my Firepower and not any single other game I’ve put the protector on.
Also, for further context, that Firepower has brand new pop bumpers and skirts. All I could figure is that the angle, and the “roughness” of the two plastics can catch randomly.
You can also trim the protector with a sharp hobby knife. It might be worth shaving a tiny bit on the protector you are talking about. I would have to see it, but in general I modify them to fit.
Hope that helps.