The search results are incomplete. Solution: Go back to the Index Manager and ensure you added all relevant folders. Also, check that your index was rebuilt after the last document edit.
Once your index is built, using it is incredibly simple: index of foxit reader
If your daily workflow involves hunting through massive PDFs, relying on standard search is like trying to find a book in a library without a card catalog. The Foxit Reader index feature turns your PDF experience from a frustrating scavenger hunt into a precise, instantaneous lookup. The search results are incomplete
However, if you have the right version, here is the step-by-step process: Once your index is built, using it is
"Search in Index" is grayed out. Solution: You are likely using the free Foxit Reader, and the PDF you opened does not have an embedded index. You need a Pro version to create the index, or ask the document author to provide one.
Click or "OK" . Foxit will process every word in every PDF. This might take a few minutes for large document sets. Once complete, you’ll see a confirmation.