There may be differing errors.
One possible error example from the remoteJob log:
To produce (export) these types of problematic PDFs
1. In the Export template choose to export the file as an image but to PDF instead of TIFF.
Or
2. In Analysis and Review, click on the download link. Provide the native PDF with the export results.
PDF is a supported format for Veritas eDiscovery Platform however there are a number of Adobe tools and programs that create very complex PDF's. This may include a PDF with macros, motion graphics or layers of complex graphics. It is known that eDiscovery Platform is challenged with rendering (imaging) these complex PDFs.
A couple of such Adobe products:
The program that created the file can be determined by opening the native PDF.