Safari downloads PDF files instead of displaying them.

From the Safari menu bar, select

Help ▹ Installed Plug-ins

Besides the following, what plugins are listed?

iPhotoPhotocast

Java

QuickTime

Shockwave Flash

Back up all data.

Triple-click anywhere in the line of text below on this page to select it, the copy the selected text to the Clipboard by pressing the key combination command-C:

/Library/Internet Plug-ins

In the Finder, select

Go ▹ Go to Folder

from the menu bar, or press the key combination shift-command-G. Paste into the text box that opens by pressing command-V, then press return.

From the folder that opens, move to the Trash any items that have "Adobe" or “PDF” in the name. You may be prompted for your login password. Then quit and relaunch Safari.

Back up all data before proceeding.

Please triple-click anywhere in the line below on this page to select it:

defaults delete -app Safari WebKitOmitPDFSupport

Copy the selected text to the Clipboard by pressing the key combination command-C.

Quit Safari. Launch the built-in Terminal application in any of the following ways:

☞ Enter the first few letters of its name into a Spotlight search. Select it in the results (it should be at the top.)

☞ In the Finder, select Go ▹ Utilities from the menu bar, or press the key combination shift-command-U. The application is in the folder that opens.

☞ Open LaunchPad. Click Utilities, then Terminal in the icon grid.

Paste into the Terminal window by pressing the key combination command-V.

Wait for a new line ending in a dollar sign ($) to appear below what you entered. You can then quit Terminal. Test.

Please open one of the PDF's on this page:

Apple - Support - Downloads

Same?

The manuals are all PDF's.