OAI-PMH Harvester Error: Attempt to read property "id" on null

Omeka Classic Plugins
1

I’ve been unable to harvest 5 new records to an existing set that has 10 previously-imported/harvested records.

The plugin status log shows the following:

Error: Attempt to read property "id" on null

I’m not sure what is the null object in question or how to address it.

Additional details

OAI Source: https://engagedscholarship.csuohio.edu/do/oai/?verb=ListRecords&metadataPrefix=oai_dc&set=publication:crohc544

The 5 new records do appear in the OAI source, along with the 10 previous ones.

The 10 previously-imported records are available in the destination site and their identifiers in the XML (e.g. oai:engagedscholarship.csuohio.edu:crohc000-2663) match up with what I see in the destination database table omeka_oaipmh_harvester_records.

I did change the name of the set in both the source and destination (collection title) after the initial harvest. Perhaps that’s having an impact, I’m not sure. Neither the original name (“Near West Side Housing Activism”) nor the updated name (“Near West Side Community Activism”) appear in the OAI source XML but to troubleshoot I did change the name of the set in the omeka_oaipmh_harvester_harvests table to the updated name just in case the plugin is looking up the collection using that name (rather than using the stored collection_id, which I’d assume is what it does)

I’ve reset the harvest several times (manually editing the relevant row in omeka_oaipmh_harvester_harvests to show a status of completed and resetting the timestamps for start_from, initiated, and completed). I’ve tried setting those dates to before, after, and the same as the dates of the first successful import.

Using OAI-PMH Harvester version 2.0.4, Omeka 3.1.2, PHP 8.0.3.

2

Well, that was a lot of troubleshooting for what turned out to be my own dumb mistake. The destination collection was the null object because I accidentally deleted the wrong one during an earlier failed import. Updating the collection_id (to one that exists) in the database fixed the issue. Hopefully all this info may still be useful for someone someday somehow.