DLC from GG unable to be added to steam

[redcxe]

I bought the CK2 Collection on GG a while back and wanted to add it to Steam. The main game worked but all the DLC that came with the pack will not add to my account- I get the error that its a Duplicate Product Code.

Any ideas?

 

[AndrewT]

Contact GG support at support@gamersgate.com .