Invalid Receive In error is issued in the following situation:
Output parameters with (<data type>) data type can only be received in the request body
In a REST API method, you are trying to change the 'Receive In' property or the 'Data Type' property of an output parameter.
Change the 'Receive In' property of the parameter as indicated in the error message.
Double-click on the error line to take you directly to the element where this situation was detected.