Weird Preview glitch

Usually I can open any pdf file by double clicking it.

Yesterday I got a bunch of files for a new job on boarding. Most of them opened without a problem, but several of them opened to this message:

"Please wait...

If this message is not eventually replaced by the proper contents of the document, your PDF viewer may not be able to display this type of document.

You can upgrade to the latest version of Adobe Reader for Windows®, Mac, or Linux® by visiting http://www.adobe.com/go/reader_download.

For more assistance with Adobe Reader visit http://www.adobe.com/go/acrreader.

Windows is either a registered trademark or a trademark of Microsoft Corporation in the United States and/or other countries. Mac is a trademark of Apple Inc., registered in the United States and other countries. Linux is the registered trademark of Linus Torvalds in the U.S. and other countries."

I cannot for the life of me open these files!!! What's going on. Can anyone help? I tried using Notes, Text edit and Google drive... but no love.

Any thoughts?

Julie