Hmmm, it looks like maybe you made some changes so that some of the conversions are now working. I had several with NULL in the message and i can't find any of them now. So that's good!
Here's one that still has a conversion error with a cryptic message, URI https://api.stage.sinopia.io/resource/2fbf1ee8-b738-43d2-a3f6-aa9cf344bd19 I can make some guesses, as it converted before and then i made revisions that broke it. Following Nancy's model of cataloging aggregates, l de-linked this from the two contained works (it was an instance of 2 works though only 1 showed up in conversion) and linked it as instance of to a newly created work which now links to the contained works as related works. The old records had separate admin metadata but the newly linked work has embedded admin metadata.

Hmmm, it looks like maybe you made some changes so that some of the conversions are now working. I had several with NULL in the message and i can't find any of them now. So that's good!
Here's one that still has a conversion error with a cryptic message, URI https://api.stage.sinopia.io/resource/2fbf1ee8-b738-43d2-a3f6-aa9cf344bd19 I can make some guesses, as it converted before and then i made revisions that broke it. Following Nancy's model of cataloging aggregates, l de-linked this from the two contained works (it was an instance of 2 works though only 1 showed up in conversion) and linked it as instance of to a newly created work which now links to the contained works as related works. The old records had separate admin metadata but the newly linked work has embedded admin metadata.