Have you installed any third party plugins or extensions recently?
From your Safari menu bar click Safari > Preferences then select the Security tab.
Deselect: Allow all other plug-ins. Quit and relaunch Safari to test.
If that made a difference, instructions for troubleshooting plugins here.
If it's not a plug-in issue, select the Extensions tab. If there are any extensions installed, turn that OFF, quit and relaunch Safari to test. If that made a difference, uninstall one at a time, quit and relaunch Safari until you find the culprit.
If it's none of the above, did you install anti virus software recently?
message edited by: cs
1. Quit Safari.
Hold the shift key down and relaunch Safari.
2. Reset Safari.
Click Safari in the menu bar.
From the drop down select "Reset Safari".
Uncheck the box next to " Remove saved names and passwords".
3. Empty Caches
Safari > Preference > Advanced
Checkmark the box for "Show Develop menu in menu bar".
Develop menu will appear in the Safari menu bar.
Click Develop and select "Empty Caches" from the dropdown.