pdf isn't PDF

Morning.

I’ve imported an email with an attached PDF file. Unfortunately the file name was name.pdf" - with a quotation mark rear the letter f. After the import DTPO did not recognize this file as an PDF, but considered it for unknown. For exemple: No preview were available. Therefore I’ve changed the suffix from pdf" into pdf. As a result, the file icon changed from an empty sheet into a generic PDF file, and the file content appeared. Now DTPO recognizes the file as type pdf, but not PDF, as it normally does. Strange to say, that it’s impossible to magnify the display of the file by Cmd+, and it is impossible to OCR the file. As well the file icon is a generic PDF icon, but not an small preview.

What can I do, to make it a »normal« PDF file?

Thanks in advance! Kind regards, Friedrich

Perhaps your correspondent needs to send you better instance of that PDF?

Just reimport the file with the fixed extension.