Can you sue rebuy for that?

I had sent a Nintendo 3ds for rebuy so I wanted to sell it and it was in top condition although it is used, it worked perfectly and now I got the message that it had moisture, which can't be. Can I sue Rebuy if the console is broken and they send it to me like this?

The moisture stickers in the console are probably red and that's why rebuy doesn't want them. This can easily come from sweaty hands.

You can sue rebuy for anything, whether the lawsuit is accepted and you win is another question.

Moisture sticker? What is this exactly?

Basically there are small stickers in every device, when they are exposed to moisture they usually change color to red. This is an indicator of the manufacturer or in this case the buyer that the console has been exposed to moisture in some way.