A selector value is used by more than one case. It might be in the middle of a range in one of the cases. When you have a Case structure, each selector value must uniquely map to a case of the structure.

For example, the second case of the Case structure in the following illustration handles selector values from one to ten, inclusive. The first case tries to handle the selector value of two, but the second case already handles this case.

To correct the error in the previous illustration, change the second case to handle the values of one and three through ten, inclusive.