Adobe Acrobat Reader DC error

Hi

When i try to open certain PDF documents which have been scanned it from an A0 scanner i get the following:

Adobe Acrobat Reader could not open.... because it is either not a supported file type of because the file has been damaged (For example, it was sent as an email attachment and wasnt correctly decoded) I have tried to rescan this document to PDF 3 or 4 times and each time i get the same error. I have also repaired Adobe and ran the Check for updates. I have also followed the following article https://helpx.adobe.com/acrobat/kb/pdf-error-1015-11001-update.html

This doesn't seem to fix the issue. Any ideas?

TIA