State Supreme Court Justice John Walsh dismissed the case Tuesday.
Brown's real name is Inga Marchand. She's pleaded not guilty to criminal contempt.
Prosecutors say Brown violated the order in July 2010 by screaming at neighbor Arlene Raymond before bending over and baring her buttocks while shouting an obscenity.
The 31-year-old Brown was issued the order of protection after pleading guilty in 2008 to menacing Raymond with her cell phone.
The two had been in a dispute over Brown blasting her car stereo outside their Brooklyn building.
The Brooklyn-based rapper was a teenager when she broke onto the rap scene as a protege of Jay-Z. More recently she's made headlines for her legal problems.
