I’ve spent quite a bit of time in 1.6 attempting to solve an iOS crash.
I’ve been calling External Functions from Action nodes, with great success in-editor.
When testing on iOS, XCode hangs up, indicating only that it was from the Execute node.
I believe I did find a solution, and so far, it has worked great.
Assuming that NodeCanvas automatically GetComponent<T> on whatever class/function you are calling is incorrect.
GetComponent on the class is necessary for building to iOS while it does not seem to be necessary in-editor.