Troubleshooting steps to resolve this error message in World of Warcraft.
Eligibility requirements for Blizzard-sanctioned events
What to do if you can't open the Battle.net desktop app, and there are no error messages when you try.
Failed to open a required file. Please check your internet connection and try again.
Failed to open a required file. Please check your internet connection and try again.
Failed to open a required file. Please check your internet connection and try again.
Failed to open a required file. Please check your internet connection and try again.
Failed to open a required file. Please check your internet connection and try again.
Failed to launch Agent or AgentSwitcher. Please close all other applications, temporarily deactivate your anti-virus software, and try again. Alternatively, log in as an administrator and try again.
Troubleshooting for Battle.net desktop app crashes.