Not sure if the CE is still being supported at this time, but when I extract all the files in the .Zip file and click on NWLauncher in the created CE directory, I get to the startup menu, click multplayer then sign-in... I get an error about the individual player key not being the multiplayer key and to switch it in the "startup" menu??
I will attach a screen shot of the error:
Not sure if you already figured it out but I'll post this anyway, in case other people have the same issues:
The GOG NWN2 Version does not provide individual installations therefore the "nwn2cdkey.ini" is empty and the game cannot verify if you are a legal owner of this game.
In order to fix this problem, open up your GOG online Account Page to figure out your NWN 2 game codes.
Then head over to your GOG GalaxyClient, select NWN2, click "More" -> "Other" -> "Multiplayer Key Changer"
This will open a small executable where you can enter the keys. Save and load and you'll be fine!
Edit: Step-by-Step-Guide: Step 1)
Log into the GOG Web-Page and head over to https://www.gog.com/account Step 2)
Under "My Collection" Click on Neverwinter Nights 2 -> "More" -> "Serial Keys" Step 3)
If you are using the GOG Galaxy Client select Neverwinter Nights 2 and Click on "More" -> "Other" -> "Multiplayer Key Changer". Enter the Codes, Save & load and your done !
If you are somehow not using the GOG Galaxy Client, head to the NWN2 Installation Directory and open the nwncdkey.ini. If no such file exists create one using text editor.
The nwncdkey.ini should contain a layout like this:
Key1=[ADD THE NWN2 MAIN-SERIAL-CODE HERE]
Key2=[ADD THE CODE FOR MASK OF THE BETRAYER HERE]
Key3=[ADD THE CODE FOR STORM OF ZEHIR HERE]
Copy and add the codes from your GOG Account, save and exit. Then try restarting the game.