It is generally very easy to make sure you are overriding the method you intend in C# - you use the override keyword and the compiler will detect any errors you make. However, it is still possible to add methods that appear to override something but do not override because they do not use the override keyword or are misspelt. Methods of this type are confusing to other programmers and may act unexpectedly.

The appropriate solution involves carefully examining the method in question: if it should be overriding another method, change it accordingly; if not, rename or remove it to avoid further confusion.

In the following example, the Sub class introduces the Foo() method, but hides Super.Foo() instead of overriding it.

In the revised example, Sub.Foo() overrides Super.Foo().

Microsoft: override (C# Reference).