The original development of our system was done before my time. We no longer have access to the person who created all work flows and tracking this issue down manually will pose a significant time delay in the launch of our new object layouts. 

 How can I track down the trigger flow error and discover what the missing criteria is? 

..If it helps, this error occured while a 'Lead' is being converted to the new objects (Account, opportunity).

See error message below.  

Error: 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 301i0000000LNHA. 
Contact your administrator for help.: [] (System Code)


Thank you!