Programs running in the background can interfere with the Battle.net Update Agent. Close any running background applications.
Restart your computer to clear its memory and free up system resources that your game needs to run.
You may experience errors when Battle.net Update Agent files are missing or corrupt. Delete the Battle.net Tools folder to have the Battle.net Update Agent automatically re-create necessary files.
If the issue persists, uninstall and reinstall the game.
Uninstalling and reinstalling the Battle.net App may resolve rare launcher issues.