After each suggested step below, it's worth re-launching to see if the game now loads.
- First try exiting and restart Steam
- Then make sure your Mac is fully updated
- If that doesn’t work, exit Steam and rename the ClientRegistry.blob and restart Steam
- If you’re still having issues exit Steam and delete everything except SteamApps under the Steam installation directory, ~/Users/[username]/Library/Application Support/Steam, this will force Steam to update when you log in
- Complete the Verifying GCF Cache Files process to repair your game cache files.
- If the issue persists, it may be caused by a network configuration issue. Please complete the Troubleshooting Network Connectivity guide to further assess the problem.
If you have completed all of the above without being able to resolve your issue, please create a thread within our technical issues/crashes sub forum which can be found here - https://community.sigames.com/forum/577-crashes-technical-issues-mac-and-linux/
Please include as many details as possible and list any troubleshooting techniques you’ve tried already so they can help you in the most efficient way.