From: Coventry, England
I bought all 3 US Corps packs from Matrix at the same time today, when I checked on Matrix site only one of them had been automatically registered (44-45), so I registered the other two on Matrix site, all seemed ok.
Then I went to Slitherine site, registered all 3 serials again, then went through the redeem key process to get the 3 steam keys, all seemed ok.
But when I activated them in Steam, 44-45 and 43 activated ok, but 42 comes up with a Steam Message about it being a Duplicate Product Code and has been used.
US Corps 42 is the only Pz Corps DLC showing as unbought in steam store?
Edit - Well after doing the redemming at what was the old page, I went to the new page that Iain links to above and "Get Steam Key" was still showing for US Corps 42 even though I had already redeemed a steam code for it on old page, so I used that steam code from the new page (it was a different code) and its activated ok now.
< Message edited by Budge4 -- 6/4/2016 1:42:20 PM >