Client Error Messages on Mac
Game cannot be opened
On Mac OSX, if you get an error that the game cannot be opened, you can work around it by entering
xattr -r -d com.apple.quarantine /Applications/RuneScape.app/
in the Terminal.
To open the Terminal on OSX, open your Applications folder, from this, open the Utilities folder and select "Terminal".
You can also try running the downloaded executable directly, or running it from the .dmg file.
Black screen when loading
If you get a black screen when initially loading the game client, check to see whether the Java version of the game client works. The Java version of the game client is available at the bottom of the downloads page on the RuneScape website.