Adding a bookmark or a web page to the reading list in Safari causes freeze

Try to reinstall Safari.

1. Uninstall by...

   • ...dragging /Applications/Safari.app to the trash.
   • ...using a free cleaning tool. This tool will also remove preferences files in the library. Therefore bookmarks and extensions will be removed aswell.

2. Download Safari from the apple website and reinstall it.

1. Quit Safari (Make a backup of all the data of Safari)

2. Delete all Files in ~Library/Safari/

Caution: This will delete all information stored in Safari. Safari will react as if it would have been freshly installed.

1. Start Safari (Safari will reproduce all files you deleted)

Voilà! Error solved the brutal way. Safari is able again to add bookmarks.