react-native: [0.29] Packager server terminates with debug on, on Node 6.3.0

In my app, since updating to RN 0.29, I’m hitting the following redbox error:

Runtime is not ready for debugging. Make sure Packager server is running.

This happens consistently once I start testing my app in iOS 9.3 simulator. I reload, then same above redbox shows, and the Packager server then actually quits (also consistently). Error in Terminal before it quits:

 ERROR  out of range index
RangeError: out of range index
    at RangeError (native)
    at fastCopy (/Users/garyfung/Documents/code/flow_search/node_modules/ws/lib/Receiver.js:386:24)
    at Receiver.add (/Users/garyfung/Documents/code/flow_search/node_modules/ws/lib/Receiver.js:86:3)
    at Socket.realHandler (/Users/garyfung/Documents/code/flow_search/node_modules/ws/lib/WebSocket.js:800:20)
    at emitOne (events.js:96:13)
    at Socket.emit (events.js:188:7)
    at readableAddChunk (_stream_readable.js:177:18)
    at Socket.Readable.push (_stream_readable.js:135:10)
    at TCP.onread (net.js:542:20)

See http://facebook.github.io/react-native/docs/troubleshooting.html
for common problems and solutions.
~
Process terminated. Press <enter> to close the window

Same error, screenshotted:

I have not gotten any consistent quitting like this in the Packager server, before RN 0.29. Before updating today, I was on RN 0.25.