Paste option not working in Safari

Sometimes the background process that handles "Rich Text" (formatted) pasting gets stuck, while the "Plain Text" (Match Style) process keeps working. You can force-restart this without restarting your computer.

1. Open Terminal (Cmd + Space, type "Terminal").
2. Type this exact command and hit Enter: killall pboard
3. Close Terminal.
4. Try to paste in Safari again.