Scanned PDF's with ABBYY FIneReader are no visibles in PDF tab

I have a problem with the PDF tab. I have many scanned PDFs with ABBYY FineReader program. These PDF files contain text behind the image. When I load a PDF in the PDF tab all goes well, recognizes the text and adds in the Rich Text tab. It is also visible in the Attachment tab. But in the PDF tab you can not be viewed. In some page is visible a dotted gray line.

The PDF tab uses a built-in

The PDF tab uses a built-in viewer. Some non-standard PDF file may not be displayed correctly. In such cases, please use the "Attachments" tab instead.