@TP-Link_Deco 

May i ask why the update is not pushed in the app? 1.4.0 is really a major update in terms of functionality and should be used by everyone.

Technical or marketing reasons that you want everybody to be on the latest?

Is the app upgrade possiblity broken in the app for m9 v2 for some reason an no firmware will ever be released that way?

@SrDarkWarrior 

I unpacked my box yesterday and it's a flat ethernet cable with no markings whatsoever so I have no idea if mine is cat6 or cat5e I found that odd

@e3henri 

I was wondering the same thing I'm very apprehensive right now about doing this update because I don't want to screw it up I really want to do it to enjoy the improvements and functionality and more importantly the stability and security enhancements that they advertise in their website but I really feel like this is a really screwed up system they got going on right now

@THEPRFCTEN I advise everyone to make the new update by connecting the decos using an ethernet cable so that they do not have any problems.

@cacb I can confirm that the slave decos will also update wirelessly as that is what I was able to do.

My main deco was connected to a switch and the system I ran the upgrade tool from was connected to that switch. The first slave was also hardwired to the main through that switch and the second slave was wirelessly connected. Running the update tool from the system connected to the main deco all three decos were updated to the new firmware. 

@Sleater14 

It shouldn't be this hard

@TP-Link_Deco 

I think trere is a problem in that deco (not in the others two). Mybe it is fabric defect. 

I have reset this deco, disconect the other two and installing only the problematic deco in its own net, so it is the Master. 

I run the upgrade, but when it must to restart to finish the upgrade, the Led flash in green but never PASS to solid green. I desconect the deco and reconect and it works, but without the upgrade. 

Finally I have reinstalled my 3 Deco system (2 upgraded and 1 with the old firmware version) 

@SteelPolaroids Thank you, that is good information!

The Deco M9+ V2 is really an excellent product, but the upgrade is causing more confusion than necessary. It kind of looks like there has been a change of technical personnell with different focus between V1 and V2. The M9+ V2 is sold with app-only control (the shop didn't tell me about V1 and V2 differences), including an in-app feature for firmware upgrade. But when the much delayed V2 firmware arrives the app-upgrade cannot be used, this looks strange. That said, I am happy with any form of upgrade and that a web interface is available in the new firmware and I am looking forward to using it. The only thing is that the firmware release could have been planned end executed a bit better. At least I suggest TP-link push the upgrade to the relevant local download sites, there is still no sign of it on my local Norwegian TP-link download page.

I'm happy to report that somehow wirelessly I was able to use my Windows 10 laptop and upgrade all 3 units! I honestly don't know how it worked but it did although the instructions in the zip file are wrong and crappy.

I think the version is the latest, anyone care to verify for me???

@THEPRFCTEN 

nope. That's the beta version that was circulating and not the official 1.4.0 release version with a date of March 23rd 2020. 
Somehow you installed the wrong bin file and maybe downloaded the beta version. 
sounds like you didn't use the update utility and maybe used the command prompt method from the beta version. 
that method will probably work with the official release bin file though instead of using the update utility program that doesn't log in on windows 10 64bit.