problem with non existing structures in 1.15.2

i like modding minecraft, so this issue was encountered multiple times.  when i enter an area where there should be a structure that already partly loaded or not, game crashes. im really unsure why this thing happens, but maybe if minecraft did'nt force itself to generate this, the bug would be gone. thanks! also, this thing i'm curently witing in is kind of confusing and counter intuitive, sorry for false information.