Owned Merchant

I m using Lesser Merchant always, working fine for past 2 weeks, then suddently after put my last merchant on the field and selling my items, i attempted to buy a new one and now i got a "not enough space in inventory to buy this merchant", my inventory is totaly empty... So i goes to Camelot to buy it from the Master Merchant Seller, same thing "not enough space in inventory to buy this merchant". Something happened with the last few patch...

Thanks.