The big stumbling block between WWE and Sting could be over opponents. It is unbelievable that they didn't book him against The Undertaker in his first year with the company. They had every opportunity, be it at WrestleMania, or SummerSlam, or even Night Of Champions or Hell In A Cell. Sting against Taker could have happened. Going forward, that could be the issue. Maybe Sting isn't happy with WWE's proposed ideas, and maybe WWE aren't happy with his desired opponents. It could be an impasse between the two sides.