StateViewUnavailableException
class StateViewUnavailableException(val keys: Collection<StateKey>, message: String, cause: Throwable? = null) : RuntimeException
A StateViewCache cannot serve the states of keys now: the cache does not hold them and their owner cannot be read (it is unreachable, the node has no route to it, or the read timed out), or the cache's backend fails. It may serve them later; the cause says what failed.
Only an unavailable source is this exception: a state that does not decode as its view, or an error in the code that reads it, is thrown as it is, so a reader that falls back on this exception never hides a defect.