When you open a PDF file and the fonts are not rendered, this could be due to the font engine.
- Open PDF Analyzer.
- Go to Settings and select Options....
- In the PDF Preview-section, make sure the Font Engine is set to FreeType.
Try to open a PDF-file again and see if this works fine.
It might be possible that your preview is still not rendering correctly. If this is the case, get in touch with our support to see if we can help.