That depends on the document.
Can you highlight the text you are searching for with the select tool? If not, that means it's probably a scan and contains only images of text, therefore there is no text to search.
Thank you for responding. A little cross-like thing on the screen highlights words in gray. When I try to enable the select tool, it won't work and it says that it is only available if document rights are enabled. Since the document is a download from the Internet, could this affect whether you can search or not? Is it possible to convert the document to Word or something if you can't search in pdf form and how do you do it?
A little cross-like thing on the screen highlights words in gray.
I'm not sure what that tool would be. You should have an I-Beam looking tool called the select tool. It should highlight in a light blue.
If you open the PDF and go to File>Properties>Security, what does it say is allowed? Also, go to File>Properties>Fonts. What does it say in the while box (you should see font names)?
My first guess would be there is security set on the file (due to the message you got).
When I go to Files>Properties>Security, the following is allowed: Printing, Content Copying, Content Copying for Accessibility, Page Extraction and Filling of Form Fields. So what is not allowed is Document Assembly, Commenting, Signing and Creation of Template Pages.
The Font tab shows: Courier; Type 1; Encoding: Standard; Actual Font: CourierSTD; Actual Font Type: Type 1.
And the tool I described does actually highlight in a light blue. It then turns from what looks like a plus sign with the middle missing into an arrowhead.
I'm not sure if this is helpful but I hope it is of some use.
You need a third party viewer like Foxit that allows you to search image in plain text mode.