1. Stop Dropbox (If needed):
- Click the Dropbox icon in the menu bar at the top of your screen
- Click on the gear icon in the Notifications panel and select 'Quit Dropbox'
2. Download the newest version: www.dropbox.com/install
3. Open your Terminal app (Located at /Applications/Utilities/Terminal)
4. Copy and paste the following lines into the Terminal, ONE AT A TIME, and press ENTER after each one. PLEASE make sure you copy and paste these commands (don't type them by hand), as getting them wrong could cause some harm. You'll be prompted for your computer's admin password (not your Dropbox password) after entering the first command. Keep in mind that the password field in the terminal will remain blank as you type your password. After you type it, just press ENTER.
sudo chown "$USER" "$HOME" sudo chown -R "$USER" ~/Dropbox sudo chmod -R u+rw ~/Dropbox sudo mv ~/.dropbox ~/.Trash/dropbox.old sudo mv ~/.dropbox-master ~/.Trash/dropbox-master.old sudo chmod -N ~ sudo mv /Library/DropboxHelperTools ~/DropboxHelperTools.old
5. Open the .dmg file from step # 2 and double click the Dropbox icon to install Dropbox.
6. Restart Dropbox from the Applications folder.