Remove Internet plug-ins and other add-ons
You can remove Internet plug-ins and other add-ons to learn whether any are causing the issue. To find them, quit Safari and open these Library folders:
The Library folder at the top level of your hard drive. Open it from the Finder by choosing Go > Go to Folder from the menu bar. Then type /Library and click Go.
The Library folder in your home folder. Open it by holding Option while choosing Go > Library from the menu bar.
The Library folders contain the following folders for add-ons. Move any files within these folders to the Trash.