Karen Waver, mayor of Flint, MI is so fed up with the state for its role in the cause of Flint's water fiasco and its ongoing unwillingness to help fix the problem that she started the process to sue the state.
The state quickly changed the rules to prohibit Flint from suing the state.
Because Flint went through economic problems and had an emergency manager up to April 2015 the city still has a Receivership Transition Advisory Board. This board declared Flint can't sue Michigan without its approval. So, yeah, the state gets to approve whether the state can be sued. Are we surprised the board is GOP appointed and controlled?