Might just be me but I'm hosting a server and every time someone tries exploring outer end biomes the console fills with this
[Server] Worker-Main-22/WARN [co.by.BYG/]: BYG's End Void Layer: Unknown biome id: -1
and this
[Server] Worker-Main-23/WARN [co.by.BYG/]: BYG's End Layer: Unknown biome id: -1
then it crashes with a stack overflow error not sure why

send the full log, little snippets doesnt help here

This should be resolved in latest