Error message
In the message, %s marks a value that the engine fills in when it raises the error.
The story
A message crossing between nodes was refused because one of its addresses was not a proper address. Here is the setup. Every crossing, whether a letter, a remote read, or an answer, carries a source and a destination, each one an identity chain in its byte form. For a letter, the destination must also include a gtrID segment, the final part that says which thread gets it. Rush refuses three kinds of trouble. A uid the byte form cannot accept. A spelled coordinate that is not a chain. And a letter whose destination has no thread segment. The delivery service never guesses an address, because a letter delivered to a guessed address might land in the wrong house. On the serving side, a refused request is answered with no answer, which means nobody was found to receive it. The first slot names which part broke. If you build frames yourself, check that every uid is a full chain of sixty-four hex segments, and that a letter's destination ends with the thread's id. Then send the crossing again.
Text from the Rush engine's error catalogue.