This type of issue indicates that an activity node is never used and, therefore, some steps may never get executed.
This situation is not an error. Thus, you do not required to change your block specification. However, it is a good idea to check the behavior of your block with the animation tool. There might be behavior that you did not intend.
An example of this type of situation is depicted in the following figure.
The analysis will report the warning Pin others is never passed, as this pin is connected with a flow but never passed by any activity step.