In every state in this country one's employement is "at will" unless there is a written agreement to the contrary. An "at will" employment means that an employer can terminate an employee essentially for any valid and non-discriminatory reason.In you situation, it is unfortunate that the employer terminated you for some issues well after the fact of your probation completion where the basis for your termination was something that happened when you were supposedly on probation.I suggest that you make an unemployment claim now that you have been terminated and regroup by planning your next round of job applications. While you are receiving unemployment benefits, you will be interviewing and hopefully receiving a better job shortly.Good luck.