Merchant Tab unable to use

After selling 1 item in my merchant tab, it now cannot be used anymore, when i attempt to put an item in it plays the sound that is played when u cannot place something somewhere.

https://cdn.discordapp.com/attachments/405874785038368818/1434124612240674886/image.png?ex=69073020&is=6905dea0&hm=7382de77625f17b5c2a5851bb25cae56ff668a110b103f5dea0eb16cc339356a&

https://cdn.discordapp.com/attachments/339154251450155018/1434127651995517029/image.png?ex=690732f5&is=6905e175&hm=9aeee29d663d38bc8e9cdd0b3e766776422eb0397ea855e8a31d0c015b9ea9ed&