how to install monodevelop?,how to open monodevelop?

i create a new c# script and I try to open it.but it says that I didn’t " install monodevelop correctly for example GTK# " how can I escape from this problem and open my script to create my game please answer me now

Well did you try reinstalling Unity. If that didn’t work install monodevelop from their website. These are some pretty easy things you should have done before posting this question.