Minecraft v1.15.2
Forge v31.1.61
Productive Bees v0.1.2
Biomes You'll Go v0.3.3-Beta
Terraforged v0.0.13

My server world has both Biomes You'll Go and Terraforged installed, which may be causing a crash with Productive Bees.
Crash Report

Thank you for the report. I've recreated the issue just with BYG when using the BYG world type.

Issue seems best fixed in BYG. Opened an issue there https://github.com/Voronoiii/BYG/issues/28