Sync gateway kills client side replication

My replication process is stopping as soon as it starts (in IOS). Here’s the logs I see from Xcode

23:11:22.773‖ WARNING: CBLRestPusher[http://192.168.1.185:4984/sync_gateway]: _bulk_docs got an error: {
    error = "bad_request";
    id = "-Slq4E65UoYSjVaFvumjshJ";
    reason = "Missing data of attachment \"undefined\"";
    status = 400;
}
23:11:22.773‖ WARNING: CBLRestPusher[http://192.168.1.185:4984/sync_gateway]: _bulk_docs got an error: {
    error = "bad_request";
    id = "-WW33azkSvOZ7oFsk_vK7Tz";
    reason = "Missing data of attachment \"undefined\"";
    status = 400;
}
23:11:22.773‖ Replication: CBLRestPusher[http://192.168.1.185:4984/sync_gateway] took 0.086 sec; error=Error Domain=CBLHTTP Code=400 "400 bad_request" UserInfo={NSURL=http://192.168.1.185:4984/sync_gateway/-WW33azkSvOZ7oFsk_vK7Tz, NSLocalizedFailureReason=bad_request, NSLocalizedDescription=400 bad_request}

I’ve been playing around with attachments so its entirely possible that there’s a bad document in there somehow. But It should kill the replication ion process, should it?