"Cos document table full" errors when trying to batch sign a drawing package with more than 256 signature fields

[aamezey]

I am working to sign and stamp packages of civil engineering drawings using a batch process, but I continue to receive an error stating "Your signature appearance file appears to be corrupt.  Would you like to delete this file?  Acrobat error.  Cos document table full."  Through research online, I was able find that Acrobat tends to throw "cos document table full" errors after placing 256 signatures or stamps on a document using a batch process.  Indeed, the first 256 signatures applied just fine on my package.  I am wondering if there is any way that I can get around this error and continue to sign my drawing packages past 256 fields.  I tried clearing the temp and %tmp% folders on my computer as someone suggested, but that didn't fix anything as far as I could tell.  Yes, I know batch applying this many digital signatures is ludicrously time consuming, but these are civil engineering drawings and every single sheet must be sealed and stamped, so there's no way I can get around the batch process.  The client has requested digital signatures from now on, so I can't simply copy and paste a PDF stamp across all sheets and then use a digital signature on the first page as an overall validation.  Would splitting up the package into smaller bits, signing them, and recombining still maintain the validity of the signatures?  I know you couldn't do that using Bluebeam or it would invalidate all the signatures permanently.  Any suggestions would be greatly appreciated, this is driving me crazy.

[Test Screen Name]

Signatures are per-document, not per page. This problem often happens when a misunderstanding of digital signatures happens in a migration from paper signatures. Signing each page is absolutely wrong. This must fail, and long before this point will produce hopelessly unstable documents.

If required put stamps on pages, then sign the document once.

[Test Screen Name]

To add some more from your question:

> The client has requested digital signatures from now on, so I can't simply copy and paste a PDF stamp across all sheets and then use a digital signature on the first page as an overall validation.

Yes, you can and you must. EXCEPT that the digital signature is not on the first page at all, it's on the document. Many people have been confused by the signature appearance, but these are misleading. In my view they should be absolutely banned, because they encourage end users to LOOK AT THE APPEARANCE which is worthless instead of the actual signature.