This error occurs when the Blizzard Launcher cannot write patch files to your hard drive. This can happen when the launcher doesn’t have permission to write files or when there’s a problem with your hard drive. Follow the steps below to resolve the issue.
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If you have tried all of the steps for your operating system and still require assistance, please visit our Technical Support Forum (World of Warcraft) (StarCraft II) (Diablo III) (Hearthstone) or contact us.
Article ID: 544