When you define a User-Defined Function that depends on itself, either directly, because its Definition mentions itself, or indirectly through a series of function calls, you create a recursive or cyclic dependency. Unless you did this intentionally in order to implement a recursive function, you probably made a mistake. This message can assist you in finding where the mistake lies. The sequence of functions listed on the second line shows you how the dependency arises.
If you intended to create a recursive function, then just check the checkbox in the error dialog. This will set the Recursive attribute for the function, so it will accept a recursive definition without error.
If you created the cyclic dependency by mistake, edit the function definition to correct it.