pdf viewer can't print

What are you calling the "viewer"?

When you Option key -> Left mouse click your PDF ends up in your Users - >yourname -> Downloads folder.

You can open the document from there using Preview App.

Preview is able to print with a simple command-P.

If you get a popup window that shows the PDF that's called Quicklook, and an option to "Open in Preview" in the top of the window. If you don't like Preview's capabilities, you can go to http://www.adobe.com/ to download Adobe Acrobat Reader and use it to open PDFs.

Compress the PDF viewer App itself and delete the stand alone App. That will force the browser built-in viewer to run. It offers a floating icon when you hover over the bottom of the document window to offer you the chance to print or open in Preview. The Preview App can print the document as well.

If you want to, you can Option click the link to get to the PDF to download the file and then open in the Preview or Adobe Acrobat Reader application.