Reproduces on Master (7421e9d5b3)
Doesn't reproduce on 8.0.0 or 8.x.x/release (d8a65b0c70)
Repro steps:
1. Create two subgraphs, referred to as subgraph 1 and subgraph 2
2. open subgraph 1
3. drag and drop subgraph 2 into subgraph 1 and connect it to the output
4. press "save as" and save over subgraph 2
5. Now that you have created a recursive subgraph, close the project
6. Reopen the project, create a shadergraph and try to open it or try to open any existing shadergraphs
Expected result: the shadergraph will open
Actual result: no shadergraphs or subgraphs will open, errors will be thrown when attempting to do so