Error 14 for saving or printing PDFs via Adobe Acrobat Pro

Hi there, 

we generate PDFs via a web application. 

Around 50 % of them generate an error in Adobe Acrobat Pro while pressing save us or print. 

The other 50 % go through smoothly. I already checked the content of the files (job applications) they contain only text and no special characters were used. 

We are able to reproduce this behavior on three different machines. All have the latest version of Adobe Acrobat Pro. 

We're aware that using for instance Macs native viewer or Acrobat Reader this issue doesn't appear. 

For reasons, we want to use Adobe Acrobat Pro and it's frustrating to see, that we can handle (i.e. view) the PDF properly but cannot save them. 

Can we do something within Adobe Acrobat Pro to make these PDFs work, so that the app ignores error 14? 

Or do we know what causes precisely this error?