On MC 1.12.2, scanning structure causes game crash.
After scanning a structure (switched on "include in game immediately?" checkbox), I reloaded MC but it crashed. The error message is below.

The game crashed whilst there was a severe problem during mod loading that has caused the game to fail
Error: net.minecraftforge.fml.common.LoaderExceptionModCrash: Caught exception from Ancient Warfare Structures (ancientwarfarestructure)

And if I don't restart MC, new template doesn't appear in choices of the structure builder.
I tried it on MC ver.1.7.10, it worked out normally.

I found what happened.
The exported .aws file (config/ancientwarfare/structures/included) was empty.
I opened it by text editor but nothing written on it.

I have fixed saving and some additional issues in the latest release on CF.