Workflow graph disappearing after node deletion

[stvdwtt]

After I delete a single node in my workflow, after refresh sometimes the workflow graph is never rebuilt. The samples and processes still exist.

I'll add more information if I find a pattern for when it does and doesn't happen.

This really hurts my attempts to get data in, because if I make a mistake, sometimes I have to delete the whole experiment and start over.

[stvdwtt]

After more investigation, I think it happens when I attempt to delete a non-leaf node. The operation fails, but I think it puts the whole workflow into an error state.