Thanks for letting me know. Thankfully it was indeed cross-referenced subtrees and not something else.
I don’t think you will get any more disappearing SubTrees. It has to be due to the crashes, but if not and this happens again outside of a crash, please let me know.
Regarding using interfaces in the Script Control (Execute Function, Get Property etc) tasks, it is currently not possible for some minor reasons, which I will take a look and see to make it possible in a future update.
I will also take a look at adding a Check Static Property/Function condition task. It seems that I somewhat missed that, so thanks for the pointer 🙂
Finally for the selection box issue you are facing, is there any specific steps to reproduce this, considering that it is still happening to you?