Circular dependency causes crash

[keithtangtw]

Main Qn:

1. I accidentally created a circular dependency, how do I recover my project now. Is it possible to manually edit the data file, and if so where is the data file

2. screenshot shows me re-creating the bug. after joining bottom node to top one acorn will crash

a) acorn should not crash upon detecting a circular dependency upon file load. It should remove dependency instead
b) acorn should not allow circular dependency to be added in the first place.