Ceramic Jar inventory bug

When I picked up the Ceramic Jar from where the kid was on the dock, it said I already had one in my inventory and sent it to the warehouse. I tried to retrieve it from the warehouse but it says it can't because it would exceed inventory capacity. I do not have one in my inventory though. Has anyone else encountered this? I really don't need the extra essence, I platinumed the game long ago but I'm curious about the issue and any possible solution.