The feature 'old_feature' is deprecated. Please use 'new_feature' instead
A language feature used in your code (old_feature) is still supported, but that support may be removed in a future release. Instead, you should use the recommended syntax (new_feature).
One situation where this error can occur is with property overrides. Instead of overriding the property, you should override the individual accessor methods. For example:
class B { public int Prop { virtual get { return 0; } } } class C : B { public override int Prop { // CS0602, delete override keyword get { // try // override get { return 0; } } public static void Main() { } }