When I run the game from GOG I am showing version 1.4.5.1304 in the task manager.

In the launcher, the "check update" button is blinking. Clicking on it brings me to their website (the polish version even though my game is english, but there is a button at the top to change languages) where it says the latest version is 1.5
can we get v1.5 for GOG? Can we get the launcher to link to the correct page language?

Also, I used the downloader and it left 201 partial files for "setup_the_witcher_enhanced_edition-3.bin" (it managed to reassemble the file correctly, it just didn't delete the chunks)

As far as I know gog version is the latest (1.5).
Check with right-click on the game exe and look at the version displayed there.

The game is fully updated.

Go to the game folder, then System folder and locate the witcher.exe file. Right click on it to check out its properties, the version it's 1.5.0.1304.

If you have the .bin properly combined you can delete the chunks.

Yea, I already deleted the chunk files, it seemed obvious.

rightclicking on the exe shows me "1.5.0.1304". So I guess it is updated.

Which means there are the following issues:
1. Task manager incorrectly showing up as 1.4.5.1304
2. The "check update" button blinking
3. The "check update" button links to the polish page on the english version.

The game is fully updated, it's just that the game process name hasn't been updated.

Also, the launcher update button is broken because of the new website.

The 'check update' button is redundant, the game is fully updated and there will be no more updates. Ignore the update button on the launcher, or do as i do, bypass the launcher completely and launch the game from the witcher.exe.

TM incorrectly showing the version is inconsequential, hardly what i'd consider an 'issue'.