I encounter Flow error when trying to Insert record in test class:
System.DmlException: Insert failed. First exception on row 0; first error: CANNOT_EXECUTE_FLOW_TRIGGER, The record couldn’t be saved because it failed to trigger a flow. A flow trigger failed to execute the flow with version ID 3010E000000CpxD. Flow error messages: An unhandled fault has occurred in this flow
An unhandled fault has occurred while processing the flow. Please contact your system administrator for more information. Contact your administrator for help.: 
I wanted to add fault message, so I can see what is the deal, but its not displayed in setup in flows tab and I can't add in process builder either. I managed to view it in Flow Designer. But I still can't find where it's invoked from.
I haven't worked much with flows, so maybe it's a silly question, but why I can't see it in setup? To my knowledge there is no Record Sharing for flows.
Here is the not accessible flow
Here are visible flows
And here is list of processes in Process builder (I sorted by type and there is no Contact)
Interesting part is that I was able to find this flow in process builder in another related org.