often When a Gargoyle encounters life drain I get this message "disk unreadable 1. restart console 2. clean the disk off with a soft cloth"

I have tried both it doesn't fix the bug. redownloading dawnguard has helped a little so that it doesn't happen every time.

what can I do to permanently fix the bug?

The only thing I can think is to clear the Xbox cache.

Since the DLC is not being read from a disc and you have already tried re-installing it, this seems like a problem with your Xbox, not the DLC.

I will try it thanks for the help