Failed to apply patch

Hello,

I recently downloaded the WOTLK for windows. It said that it had to download a patch, after a short time of it staying at 0, it says to restart. After pressing the restart button it gives me an error message saying:
"Failed to apply patch. Please try again later. If this problem persists, you may need to reinstall or contact technical support."
I've deleted it and reinstalled multiple times and continue getting this error.
Any help would be greatly appreciated!

Thanks,
Odarion

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