Internal Error: Illegal Access  #864

Node version 6.0.0
Node Inspector 0.12.8
Express 4.13.4

1. node-debug app.js
2. open the inspector and press play
3. open the localhost:3000
4. works then set breakpoint on 'res.send() line';
5. reload localhost:3000
6. internal error: illegal access

I am aware of the issue #413 and my issue might be related. Why am I getting this error, I am not able to set a breakpoint anywhere.