Hey everyone.

I have stumbled upon a problem with the "new game+" patch in The Witcher 3.

It tells me that "This version of the base game is not supported. Please update your game version with the latest patch"

I have already updated the lastest patch, but still it tells me this.

Any suggestions?

Would be much appreciated. Thanks.

I've had the same issue.
Update the game, redownload the NG+ DLC.
The lastest version of the NG+ DLC has filename setup_the_witcher3_dlc15_2.0.0.37.exe. The old version which gives the error has filename setup_the_witcher3_dlc15_2.0.0.34.exe.