When pregenerating The End, the server crashes when hitting a chunk. I have reset The End as well to fully test and it still does it. Appears to be an issue with Biomes O' Plently that was fixed in 15.0.0.98. I'd recommend updating it, TerraBlender, and Forge (which is needed for TerraBlender). This appears to fix the issue. It isn't a hard crash but simple causes the server to close due to max tick time.