I am getting this every time i try to install the 2.1gb file i downloaded from GOG galaxy.

There's a patch for each language version.
Did you download the correct one?

i installed patch 1.07
got an error message at the end about corruption
re downloaded the patch
tried installing the patch

same message as OP gets,wrong installer

guess its just another badly tested patch

Same problem :(

I'm having a similar issue.
My 1.7 patch goes "not responding" towards the end of the patch install.
(This is on a fresh install of Witcher 3 all files dl'd today.)
My game version ends up v1.7 but I wanted to run the patch again and got the message you're getting.
I can't seem to install the Ciri dlc pre or post patch 1.7 either.
Installer tells me "This version of the base game is not supported. Please update your game version with the latest patch."

This is exactly what's happening to me right now! + GoG is forcing a 7.5gb update.

This patch has a problem after installing the game does not run at all !!!! Its shows MatchesCountError??? WTF IS THIS?,

Remove any addon you are using (console enabler for example). You must get addons for new version of the game.

Don't click OK just leave the error open and the game will still launch.

I ended up uninstalling and reinstalled v1.6 (don't forget to copy W3 saves in your documents folder.)
Applied all dlc (pre-Ciri).
Ran the v1.7 patch again, let it run even if it looks like it failed.
Install Ciri dlc after v1.7 patch successfully installs.

Good to go!

I'm getting the same thing with the 2 GB installer.

The funny thing is, I can't even download the patch "normally" via galaxy. I mean the 6.5 GB Version. (And why is it 6.5 GB anyway when the backup patch installer you can download is only 2 GB ? What kind of customer unfriendly behaviour is this ?)
I tried it 3 times now, and 3 times I got "failed" somewhere during the downloading process. The first time it was like 100 MB from completing. I'm stuck with a really slow Internet connection, and downloading 6.5 GB of patch takes me a whole day if nothing gets interrupted. Once it even said "not enough space" when there's like 30 GB of free space on the partition I'm downloading to.

It's really frustrating. The version I can download doesn't work and the version that perhaps would work can't be downloaded.

Edit: I just checked and now I can't even play 1.06 anymore, it somehow corrupted my game files in the failed patch attempts, so I'll have to reinstall everything. That's one failed patch day if I've ever seen one.

i get this when i want to install patch 1.22 and 1.21 and 1.12 some one tell me what should i do for .. it will kill me finaly