Duet Web Control connection failures

Firstly, may I say how appreciative I am of all the work people do - for free - to help make this a really approachable and rewarding hobby.

I have just upgraded my firmware and and now encounter some strange behavior when connecting from the web (Chrome browser 48.0.2564.82 m).
When I connect to my printer via the web, the connection seems to work, but the values for current temperature display n/a it also shows two hotends, instead of the one I have, exactly as it would look in the disconnected state.
If I then disconnect and re-connect, everything works correctly as expected.
If I then disconnect, the next connection is a bad one, followed by a good one and so on.

Any Ideas what could be the matter?

Firmware Name: RepRapFirmware
Firmware Version: 1.09r-dc42 (2016-01-16)
Web Interface Version: HTML: 1.08, JS: 1.08

That sounds like an issue for chrishamm rather than me, and he'll probably need a Wireshark trace from you to work out what is going on.

---

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

Thanks for the swift response Dave I'll get onto Wireshark asap.

1) What OS are you using?
2) When opening the JS console (via F12), can you spot JS errors or do you see any other error messages?
3) If some resources fail to load, could you record a Wireshark dump and either upload it here or send it to me via PM?

Running Windows 10 home 32 bit.
Not getting any JS errors.

Trace attached.. (dont know how to filter the traffic for just between the pc and printer)
The printer is .42 my laptop is .36

Worked out how to filter.
This is a trace of the faulty connect.
I hope that makes it easier...

Thanks for those files, but unfortunately I cannot spot anything suspicious in there. Can you please make another dump while loading the web interface? And this time leave the JS console open to check for possible JS errors and bad HTTP requests.

Did a connect. it worked fine. Then I did a disconnect and got this js console error:

VM111:61 Synchronous XMLHttpRequest on the main thread is deprecated because of its detrimental effects to the end user's experience. For more help, check [xhr.spec.whatwg.org].
VM111:62 GET [nikkomsgchannel]…360044002e002d00140020002b0044002b00790059005e0029005b002e002d005b002a0028 rapport_nikko_send_focus_event @ VM111:62rapport_nikko_on_focus @ VM111:72
VM111:49 GET [nikkomsgchannel]…440035002c005c00600022005900340029000a0059002b005b002a002c005c002f0028005a rapport_nikko_on_blur @ VM111:49

Does that help?

I'm afraid no. That VM111 is a built-in function in Chrome/Chromium and not part of the web interface, so I can't help here!

Without an error message or a Wireshark dump that reveals possible TCP problems I don't even remotely know what could be the cause of your problems.

I have a Wireshark dump from open page-automatic connect (good)-disconnect-connect (bad) but it's too big to attach.
What kind of thing could I look for in the dump that might give a clue?
I can live with the problem, but I'd love to make it go away.
I understand you must be busy, so no pressure!
Any advice you give is welcome...

Thanks
Martin

Well, if your dump becomes too big, you could use this filter:

tcp.analysis.flags

That will make Wireshark display only bad packets and if something goes wrong whilst loading the web interface, this will show why. But if you don't see any bad traffic between the Duet and your PC, you could also try to load the web interface in a private tab. If that works, I suggest you try to revert to the factory settings once and then reload the web interface.

Thank you so much!
I'll give it a try and post my results here.
Martin