My question involves employment and labor law for the state of: Texas

I signed a contract with my US employee to work for 3 years on H1B Visa. But after 2 years, I left the company in happy terms and every thing was fine till now. But yesterday (after one and half year of leaving company) I received a letter from my employee that I need to pay him $ 45000, because I broke the contract. I want to know that, can he still sue me after such a long time.
Please please suggest, what should i do?

Thanking you

Ari