Trying to open metrics window for PopHappinessStd-EB font crashes program

Hello,

When I try to edit the metrics of any character in the PopHappinessStd-EB font through FontForge, it causes the program to become frozen for a second, and then close due to a possible (but invisible) crash. I have attached my font file to this issue and look forward to any follow up.

PopHappinessStd-EB.zip