Well, according to the detailed message , the crane cannot reach the (target) position.
Without having a look at the model/ sub model it will turn out to a guessing, what is causing this message.
this is not an error, it is a message telling you that the target position of the crane cannot be reached.
In earlier version the crane remains at his position and throws the part to the target station. This was a bug.
Can you please provide your model so that I can examine the message in more detail?