revoked probation

My boyfriend recently found out he had a warrant out for his arrest. He was on probation in Texas for contributing to a minor with alcohol. He went to all classes and court dates for his probation and thought he had completed everything. Recently, he found out his probation officer had quit before sending him his last court date and no one followed up on this to call him or send him this information.
He now is told he will have to serve time for this, from what the judge said- a year or more, because this is a felony-- revoking probation. He is frustrated with this, because he doesn't feel he did anything wrong and due to a clerical issue will have to serve time. Is there anything he can do? I don't know how much the bail is or would be if that's even an option. Any advise on this?!?

there should be a hold put on him ,he will go to court and most likely put back out on probation

I find it interesting " he found out " his PO had quit , but did not contact the Office himself .