@hanmari 

Power down then power up every node, and try the update again in the Deco app.

If that fails, go to the support page of the Deco and download the oldest firmware version which should be 1.2.4 (build 200527), log into the web GUI like you tried, and upload the .bin file. If that works, use the app again to try and update it that way after.

@Tony Thanks for the advice. I was able to get one of the devices to switch to different firmware versions, but two of my three x60 devices remain stuck on the original firmware. I have moved the device that can change to the latest firmware into the primary position and left the other two as satellites. I hope running different firmware versions in the same network won't cause too much trouble.

These are the steps I have tried to get the remaining two devices to change firmware:

• remove all devices from the network so only the x60 units are present
• move each device to primary position, press the reset button, and rebuild the network from scratch, then update the firmware over an ethernet cable as well as over wifi
• move each device to a satellite position, press the reset button, add the device to the network, then update the firmware over an ethernet cable as well as over wifi

The firmware on two of the devices won't budge. The third accepts updates and will easily change from one firmware version to another without any trouble. I am beginning to suspect I have a couple of bad x60 devices. Does anyone know of any procedures that I could use to force firmware to flash? I am losing faith in the online tools because they always report that my firmware is already the latest even when it is painfully obvious that there have been three firmware releases since the original.

@hanmari 

See if your Deco units are different hardware versions as they have different hardware versions, you can see that on the sticker label below the unit.

I would recommend reaching out to our support team to see if the reaming two nodes may have an issue.

@Tony Thanks again for your input. I created a ticket with customer support at TP-Link and was soon escalated to a second tier technical agent. I granted him local access to my network through a Team Viewer client and he was able to remote into my Windows PC and run firmware upgrade tools and diagnostic commands. He concluded that though the units were in working order, their firmware was frozen and I would need to send them in for servicing. I was pleasantly surprised with the level of technical acumen from the second tier support representative and the online tools that TP-Link was able to provide. I have started the RMA process so should have replacement units soon.