A few bugs in 1.12 with the forcefield generator:
When I first used it, everything worked fine. I could make and delete fields, turn them on and off.
But, on occasion the generator would duplicate itself (showing an increasing stack size, and allowing me to pick up the stack and place new generators out of it).
This latest time I launched the game, I found that I am no longer able to delete any force fields. Attempting to do so has resulted in creating quite a few new single tile fields instead, which I can ALSO not delete... fortunately I can still turn them off.
Not sure if intended... but placing and deleting a field blocks water/lava flow. The flow remains stopped like a brick is in place even after the field is removed.