I have my GOG CD KEYS. Have even tried my original CD keys. I try to sign into Multiplayer and I get

"Your individual serial keys not assigned to your game. Please use the multiplayer Key Changer found under the start menu."

I have used this with my GOG keys and my original keys and can get no further.

How do I play on multiplayer servers?

Is this for NWN2? Doesn't sound like NWN.

This sounds like NWN2. I am assuming you wrote all 3 of NWN2, Mask of the Betrayer and Strom of Zehir keys and pressed Save and close. So past this, only explanation I can think of is you installed the game under program files which is not allowing you to make the changes.

So try running the Multiplayer Key changer in Admin mode and try again. Better way is to uninstall the game and then install it out of program files like C:\Games\Gog Games\.....

For multiplayer the NWN2 CD keys for the OC, MotB, and SoZ need to be in the nwncdkey.ini file that should be in the same folder as nwn2.exe (by default C:\Program Files\Bioware\NWN2 Complete. You can edit the file safely with Notepad.

Regards

So I've tried putting in my CD keys into the multiplayer key changer (with and without the dashes) and I've put the keys into the .ini file and saved it.

With the MKC, the "save and close" and the "save and launch" buttons are both grayed out.

UPDATE: Found out I was missing one letter, now the keys work fine. But I still cannot log into multiplayer