NBTTagCompound error while adding structures with chest

[Pingusman]

Plugin version: 8.0.0 BETA 4

Spigot username: Pingusman

Issue: I'm not able to add custom structures with chest, it will crash when generating ("natural" or ewg paste)

Link to settings file (world-settings.json, possibly also biome settings if you have created your own): http://discuss.dynamic-bytes.com/p/22-qulewasaci

Link to error log/crash log: https://pastebin.com/D1dGVtB1