Sell button is greyed out saying I'm using designs not mine? stuck now

[Gin22]

Ok, I'm stuck. I tried to make designs on mugs, twice. Both times the 'Sell It!' button were greyed out saying 'Zazzle wont' sell items with designs not mine'. Well, they are mine so something is triggering a 'copyright' warning somewhere? 

[Cristina]

Are you using Zazzle's icons or backgrounds? 
They're only for personal use and not for reselling