To repair Application Support file permissions:
- Open Terminal, located in /Applications/Utilities.
- Type or copy and paste the following command for the affected application:
sudo chmod 0754 ~/Library/Application\ Support/Battle.net
- Press Return.
If your system is not in English, you might need to translate Library/Application appropriately.
Note: You may be prompted for your administrator password when using the commands above. You may not see characters appear when typing, though it will accept your password.