Details on why a PDF is damaged

Hello!

I am in the process of developing tools that produce PDFs. The software produces PDFs that open correctly in all viewers except for Adobe Reader. I am trying to understand why, but all Acrobat says is:

"There was an error opening this document. The file is damaged and could not be repaired"

I have bought Acrobat Pro, so that I can use the Preflight tool - but it will not function on files that don't open.

Is there any way of getting more extensive debug information on why Adobe Reader considers the file damaged?

For files that it does open, it seems to alter the PDF (repair it) and as such it seems that even the files that open are considered damaged but repairable. If I use the preflight tool on those files, the preflight tool will fail with the message:

"The document structure is corrupt"

Any help here is much appreciated.