Google posted on their data anomalies page an update about their Jobs Postings Report saying after April 10, 2018 and onwards Google will be showing more specific errors in that report. This will help those who implement job schema to better debug any issues they have going forward.
The generic “missing or invalid field” error has been replaced by more specific error types. Existing instances of this error will be replaced by a more specific error type in this report. Items previously tagged as “missing or invalid field” will still appear in the report, but with zero instances for the remainder of the issue lifetime.
So keep an eye out for any new errors you get for this report, if you are using job schema.
Forum discussion at Twitter.