Pause and subsequent cancel causes UI to become unresponsive.

[ralxnder]

What were you doing?

Pausing and then canceling print

1. Pause current print
2. Cancel current print without resuming
3. ...

What did you expect to happen?

I expect the print job to be cancelled successfully and the UI to go back to a ready state.

What happened instead?

The UI hangs in a "Cancelling" state and is unresponsive unless I disconnect and reconnect. I cannot control my print with any of the buttons as they are all grayed out.

Did the same happen when running OctoPrint in safe mode?

Yes

Version of OctoPrint

Octoprint 1.3.8

Operating System running OctoPrint

OctoPi 0.14.0

Printer model & used firmware incl. version

Anet A8 running a MKS Gen 1.4 board loaded with Marlin 1.1.8.

Browser and version of browser, operating system running browser

Chrome Version 65.0.3325.181 (64-bit) running on Windows 10 Pro

Link to octoprint.log

octoprint.log

Link to contents of terminal tab or serial.log

serial.log

Link to contents of Javascript console in the browser

Screenshot(s)/video(s) showing the problem:

I have read the FAQ.

[foosel]

Please enable serial.log (Settings > Serial Connection > Log communication to serial.log), then reproduce the issue, then post the resulting log.

[Serray]

I had the same issue with pausing my print.
I clicked on pause print, normally it should perform the custom GCODE which i added to the pause button,
which should raise the head from the object.
The status of the printer didnt change from printing to paused.
I wasnt able to send any commands to the printer.
Also for me, all buttons were grayed out

Ruined my 7hrs print.

[foosel]

@Serray for you the same goes as for @ralxnder. I need logs. I can't reproduce this myself. I depend on logs to be able to debug this.

[ralxnder]

Here is a serial.log. I was seeing the same as @Serray, buttons are grayed out.

serial.log

[flashmani]

I also faced the same issue. To rework we have restart the octoprint. This issue is happening after the latest update.

[NeroBurner]

I found a workaround until the issue is resolved. When the pauseing gets stuck and the buttons are greyed out, then go to Terminal > Advanced Options > Fake Acknowledgement. Then the print status should be Paused

Related: #2581

[foosel]

Found and fixed by the above commit. Both this and #2581 had the same race condition as root cause. Until 1.3.9 is released (currently traveling, so can't look into this due to lack of a proper test environment) hitting "Fake Acknowledgement" as described above is a functioning work around.

[foosel]

Just to make this easier to find...

Workaround for this issue can be found here

[DrWatson]

Just wondering if this bug could cause the following problem:

I use the filament run-out plugin "Filament Sensor Reloaded" by kontakt. This plugin will call the pause function in Octoprint when the lack of filament triggers a micro switch.

I have a GCODE script populated in the "After print job is paused" section of my configuration and have noticed that, in about 1 out of 3 times or so, when the pause is triggered, Octoprint crashes completely and I have to reboot the RPi.

[foosel]

@DrWatson I doubt it. But it's hard to say without octoprint.log and serial.log and your settings ;)

[DrWatson]

Thanks for the response. I think I am going to upgrade to 1.3.9rc1 and see if the problem goes away so at least I'm on the most recent code stream.