MissingUploadUrlException
Thrown by UploadFileEventRunner when dev.catbit.mosaic.core.data.schemas.event.events.networking.UploadFileEventSchema.url is null and NetworkParametersHolder has no staged URL to fall back to either — the case SetIncomingDataToNetworkParamsHolderUrl was supposed to cover but either wasn't chained, or staged a value some other network event already consumed first.