I recently deleted some non-English voice files and video files to save disk space. And when updating the newest patch there is an Error said Error 1002 OSError_AccessInvalid.

This is the solution:
1. Find the downloaded update files, it should be in the path: ~\Steam\SteamApps\common\Zenimax Online\The Elder Scrolls Online\depot\.
2. You can find a new folder, whose name is "depot_version" or something like that, contains some .zip files which are the patches you just downloaded.
3. Open the .zip files and you can see the files it will update this time.
4. I found that I deleted some DE JP FR video files earlier, so I just unzip those video files from the patch file to its path.
5. Then everything is perfect.

This works for me and I do not have to re-download the whole game again.