I can´t tell exactly when the problem started but I can´t open PDFs from my browser... Safari... any thoughts? I don´t know if it was since the last update of my OS...
Back up all data.
Triple-click the line of text below to select it, the copy the selected text to the Clipboard (command-C):
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 (command-V), then press return.
From the folder that opens, remove any items that have the letters “PDF” in the name. You may be prompted for your login password. Then quit and relaunch Safari, and test.
The "Silverlight" web plugin distributed by Microsoft can also interfere with PDF display in Safari, so you may need to remove it as well, if it's present.
If you still have the issue, repeat with this line:
If you don’t like the results of this procedure, restore the items from the backup you made before you started. Relaunch Safari again.
Retrieving data ...