Hi marcodalle
I'm not with Laminar Research, just a fellow simmer in the UK, but the first thing to check is that your downloaded liveries are actually in the C:\X-Plane 11\Aircraft\Extra Aircraft\Boeing B737-700U\liveries folder? This assumes that you are using the X-Plane 11 simulator?
Personally I've never used the Zibo Mod B737-700U. I do however use both the B737-800X & B737-900U aircraft, in which case all of my liveries are in the C:\X-Plane 11\Aircraft\Extra Aircraft\Boeing B737-800X\liveries & C:\X-Plane 11\Aircraft\Extra Aircraft\Boeing B737-900U\liveries folders respectively.
Hope this helps?
Regards