I have been playing the World At War Custom Map Bowser's Castle, by Drew629, and I keep running into the same error. The boo freezes every time I stop him from taking away my perk. I have even allowed him to take my perk, but he still freezes. I know there is a secret area behind the Ghost Valley painting, but I can't access the area without having the boo move away from the perk. Does any know how I might be able to fix this error?

I had the same issue when I played this map for the first time. It turns out that it's an issue with the plutonium client, (assuming you're playing through plutonium) and when I tried playing the map in base waw it worked just fine. (that was the solution for me) hopefully that fixes it for you as well