That's the error I get. I downloaded the Polish version of the patch as I have done with the previous 2, but I get the same error when I grab the EN version, both have the same filename anyway:

patch_witcher3_1.01-1.05_2.0.0.32

My game version is 1.04

I am getting the same message with for the English version. I also have patch 1.04 installed, and now my game does not start at all! I've downloaded the patch twice and tried to run it multiple times.

I've attached a screenshot of the error. Please fix!

Have you tried using GOG Galaxy?

You can import the installed game by clicking on The Witcher 3, then More -> Manage... -> Import folder (and selecting the directory the Witcher 3 was installed to). It should then automatically update the game for you.

If that doesn't work, try clicking More -> Manage... -> Verify/repair (to make sure your files aren't corrupted).

Well, in my case it was because I had tempered with the exe using a hex editor. Restored the original exe and was able to patch np. :)