Having two (or more) of the same nested BT’s in FSM and then renaming the BT will cause the BT graph to completely wipe clean.
NodeCanvas v3.09 and Unity 2019.4.1f1.
HOW TO REPRODUCE :
1. create FSM
2. create BT
3. create 2 nested BT’s with the same BT on each.
4. rename BT file
5. BT graph is now reset…