Crash when handling NFC events with Web IDE connected

Strange - so you're saying that something like this:

NRF.on('NFCon', () => LED.set() );
NRF.on('NFCoff', () => LED.reset());

is fine - it's just when you print text from the NFCon event that you have problems? And the Web IDE stays connected - it just no longer prints anything. What if you disconnect and reconnect?

If you type LED.set() on the left-hand side when it's not working, does the LED still light? It might be that it's transmission from Puck.js that has broken somehow, rather than a complete crash?

I'd also be interested in whether:

NRF.on('NFCon', function() {
  setTimeout(function() {
    print('Hello world!')
  }, 1000);
} );

works - so printing, but not right at the same time that NFC starts.