Ghost button that won't dissapear

At my grid I have an old self made button, that won’t disappear. Only if I remove all my buttons. That “ghost button” is not in the list… Anybody know what to do?

🚀 Scriptcase 9.12 is now available! Check out the new features here 👉🚀 Next Monday (02/24), Scriptcase 9.12 will be released! Check out the new features before anyone else 👉