Hey there,
Sorry to hear you're facing issues with the GOG server files for this game. I encountered a similar problem a while back with a different game on GOG. A few things that worked for me:
Clearing Cache: Try clearing the cache of the GOG client, sometimes old data can interfere with new downloads.
Using a VPN: Sometimes the server you're downloading from might have issues, so switching to a different region might help.
Pause and Resume: Occasionally, pausing the download for a few minutes and then resuming can bypass such glitches.
Reinstall GOG Client: As a last resort, you can try reinstalling the GOG client. Backup your games before doing this.
I hope one of these solutions works for you. If others are also facing the same issue, it might be a server-side problem and you should report it to GOG support. Good luck!