Not an enclosing class error Android Studio

Intent myIntent = new Intent(MainActivity.this, Katra_home.class);
startActivity(myIntent);

This Should the perfect one :)

It should be

Intent myIntent = new Intent(this, Katra_home.class);
startActivity(myIntent);

You have to use existing activity context to start new activity, new activity is not created yet, and you cannot use its context or call methods upon it.

not an enclosing class error is thrown because of your usage of this keyword. this is a reference to the current object — the object whose method or constructor is being called. With this you can only refer to any member of the current object from within an instance method or a constructor.

Katra_home.this is invalid construct