Welcome to the SeeMeCNC Community

I just finished upgrading my V3 to a V3.2 and I am getting connection issues to the web console after leaving it for 10 minutes or so. I cannot reconnect with any browser on my laptop or iphone. Error message below.

Communication Error
A communication error was reported, so the current session has been terminated. Please check your board and try to connect again

Error Reason: SyntaxError: JSON Parse error: unterimated string

not sure what to do... I'd like to be able to monitor my print from start to finish....

Just had the same experience with my Duet 0.8.5
Turns out you have to upgrade the firmware in a specific order to make it work.

I had to hold the erase button on the duet, then the reset to get it to show up on USB so i could flash an old firmware to start over.
If you try this be warned you need to use Bossac.exe (command line tool) because for some inexplicable reason the version with a GUI doesn't work on any modern PC. If like me you have an older board don't rename the firmware file before uploading.

This is specific to the WiFi board but the steps order helped me solve the issue.
https://duet3d.dozuki.com/Wiki/Installi ... g_Firmware

If you upgrade the firmware in the wrong order it's no big deal, you can get them in sync again without using bossac. Just move the SD card to a PC, replace the /www folder with the contents of the correct version DuetWebControl.zip file, and copy the main firmware file (Duet2CombinedFirmware.bin) to the /sys folder on the SD card, along with DuetWiFiServer.bin if the board is a Duet WiFi. Then move the card back to the Duet and connect to it via USB. Send M997 S0 to update the main firmware, then when you can connect again, send M997 S1 to install the WiFi firmware. After that, clear your browser cache and reconnect.

In most cases you can just update everything over the network. Upgrading from pre 1.19 firmware to 1.19 or later on a Duet WiFi is the case that needs a little more care.

I followed the instructions to a "T"... not sure how I could have done it wrong.

redid the firmware. Issue still persists. Posted on the duet forum and no real progress made there. The forum did mention that there is new firmware for the board out, maybe a week old. But SeeMeCNC hasn’t updated their end yet


I got nothing at this point. My octoprint setup never had an issue so it’s not my network. Going to have to buy a panelDuo

if you think it may be a weak wifi signal you can try something like this
https://www.ebay.com/itm/AMAKE-WiFi-Rou ... rmvSB=true
i have a couple of them and for the money they work pretty good

several times my duetwifi has disconnected during a long print and i was not able to monitor the print
once i had to kill the power to stop a bad print until i figured thing out a little better
https://duet3d.dozuki.com/Wiki/Gcode
if i hook up the usb cable and send m522 s1 it restarts the wifi

I had random to severe dropout issues until I disconnected my USB cable. Now it hardly ever drops out.