My commercial tenant resigned from his lease agreement on my property?
No one 'resigns' from a lease agreement; they either honor the agreement and its terms, or they breach the agreement and sue, or you sue them. For the few bucks spent suing you, sounds like he's being proactive to get you to let him out without financial penalty. Everyone can always find something, but it's unlikely a court is going to rule against you and mediation is a requirement before getting to trial. Lawyer up, make sure you show up and defend your position, making sure to counter claim for lease terms ($$$) and any resultant $$$ losses.