DTV Import Upsert is crashing on save scenario after selecting Add another mapping for a mapped field and then clicking Save scenario.
To workaround this crash, add the additional field mapping and then select Scenario Save As.
Once you do Save As, you will also have to rename all your matching steps, as these get reset every time you use Save As.
Personally, I open the prior version of the saved scenario in a browser using http://localhost:8080/ to see the details of the prior scenario. However, Validity Support advises to never user the DTV from the browser, but it's good for seeing details from another scenario.
Uggh...this workaround only partially works. I just discovered that after you add the additional mappings, and use Save As, your additional mappings do save. And when you reload the scenario, the additional mappings are there.
However, if you change the input file, you lose the additional mappings. 😠