Searching pdf files opened in Preview

[Gus]

If I open a pdf file with Preview and use the search box to find a word, it works ONLY for pdf files that I created (for example by saving a Word file as a pdf). It cannot find anything in a pdf file created and sent to me by someone else.

 

[honestone]

I don't use Preview (preferring Adobe Acrobat Pro), but I just tried this on my Mac MIni, using the version if Preview that comes with El Capitan (OS 10.11.6). I opened up a "Covered Drug List" PDF from a prior Medicare Advantage Plan we had, and did a find (search) for "Lisinopril". It was found, and it showed the results both to the left (in a list), and the first page where it was found.

I also did it with a Samsung Manual we have for our Samsung TV, doing a find for "Internet", and once again it was found.