trade is ready will not go away

[mcpooballs]

I do not even remember what the trade was for but every. single. time. i open the website the "Your trade is ready!" popup will not go away and i cannot trade or sell anything because it says i already have had a trade up, it has been like this for a week and makes the website unusable, when i click on open trade offer it just says the trade offer is not available . please help what do I do?