Credit report says "state tax lien" what is this and what to do?

So I just did a credit report using Experian and my report is fine, but I found something under "bankruptcy and court judgements" something that says state tax lien. Under that I have the date filed, reference #, court location, under plaintiff it is empty, liability is $800, and nothing on asset amount. This is lowering my credit score by a bit. What exactly is this? How do I get rid of this and how did I get this? I am so confused. :( I've been getting state taxes deducted from my pay roll every pay day, so I don't see how I would owe the court anything. Help pleaaaaseeee. :( Thanks.