@ErnestoRamos This is the message when I tried to update the firmware of my M4R (US). as a solution for the solid yellow led. It stop at 17% and display the following:

Upgrade Failed

Failed to upgrade your Decos.
You might have chosen a wrong file. Please enter 192.168.0.1 in the address bar and try again.

  @TP-Link 

I just upgraded my firmware and now its stuck on yellow lights.. i have 3 deco E4 and the other 2 is working but 1 is stuck.

Its not the main deco but the satelite deco. Ive tried to plug the ethernet cable amd it started blinking yellow, but now its stuck there.

Ive tried to hit the reset button but no result. HELP

  @TP-Link 

My deco m5 is stuck in a loop.

1. The model number as well as the firmware version of the Deco;

Model: DECO M5 (v3)

SN: 22041Q8B00200

Firmware versions that I tried:

-Deco M5(EU)_V3_1.7.3 Build 20230906

-Deco M5(EU)_V3_1.7.2 Build 20230823

-Deco M5(EU)_V3_1.7.1 Build 20230608

2. Which problem description is more like your current issue?

One of my m5 deco's is stuck in a loop. Long yellow light -> flashing blue -> back to long yellow light.

3. Have you tried the hardware reset and firmware recovery suggestions? what are the results?

Yes, I tried normal reset and firmware recovery with the TFTP tool. Upload is succesfull but the M5 is still bricked in a loop. 

  @TP-Link 

I also have an X20 that is now permanently stuck with a solid yellow light and cannot be linked to my main unit.

I have tried the firmware recovery procedure many times now with no positive result. The light just continuously stays yellow.

SN: Y221048C00022

Not sure of Firmware Rev...

Thank you in advance for any help you may be able to provide.

  @TP-Link Did anyone get the yellow light to flashing blue resolved on the x20 Deco ? 

I can't bring up the 192.168.0.1 when trying the Uboot method.

There seems to be common thread going on here with these devices.

  @TinnyTimmay 

This issue is still not resolved for me.

Probably better to contact TP-Link via other ways, since they do not reply or comment on this thread. 

  @TP_ 

1. The model number as well as the firmware version of the Deco; Model E4R(US) Ver:2.0, the last firmware I tried to install was: E4R 1.0_en_1.5.4 Build 20211101 Rel. 75384_US_EU_AU_up.bin, also tried with: E4R 1.0_en_1.1.0 Build 20190823 Rel. 43466_US_EU_AU_JP_up.bin

2. Which problem description is more like your current issue? Solid yellow light stuck, it does not change color even after days of being connected.

3. Have you tried the hardware reset and firmware recovery suggestions? what are the results? Yes, I did tried multiple times. It lets me do the Firmware update, but it's still not changing the LED Color. 

  @TP-Link I also have issue with the BRICK YELLOW LIGHT on one of the deco unit. I cannot use it and even if I already reset it couple of times, I still can't make it to have the flashing blue light.