Hi Lutherv,
Why do your pdf's that your lib generates have a bad xref table?
I am afraid that I was not able to reproduce this issue. Our generated PDF document can be able to convert to thumbnail of the PDF.
Here is the video clip and files for your reference:
http://websamples.syncfusion.com/samples/PDF.Windows/F72714/main.htm We have used GSView to convert this to thumbnail of the PDF. Please take a look into this and if you are still getting this issue, please provide more information with system configuration to reproduce the issue in our side, so that we would sort out the cause of the issue.
Please provide your Essential Studio version also.
Regards,
Bhuvana