LOL I don’t understand any of these posts. I just installed the Xbox App and the Store picked up the new version after a few seconds. Didn’t even quit out of the Store or login in or out. I would imagine if this isn’t working then maybe there are other issues at play here?
I’m guessing folks have checked they have the latest patch of Windows and updated the Store app etc etc.
It is a frustration that could have been avoid if it was clearly noted that having the Xbox app was a prerequisite or better still invoked the installation of the app if not already installed.
The download/update process really ought to be a simple process, not all users will be using forums or social media to find these things out. The sim is available to people of of all ages with a wide range of understanding of PCs/Xbox/tech who may have no understanding of what is going on or how to resolve something that should be very simple to do.
It took me a while to find out via this forum what was causing the update loop, really something that should not be necessary for the simple task of updating the software and content.
This was not necessary for me. 
I could do everything from the MS Store ONCE the Xbox App was installed and I also just had it running in the bg.
After an hour of logging in and out of the store and xbox app, rebooting and checking for updates I finally found a way to kickstart the update: Selected the Sim in the Ms-Store and clicked on the elipse button beside the play button, thats where I found the option to update.
Thats the first time that the update didn’t start automaticaly for me.
I totally agree, the update process is a total mess. Any other decent, well coded program updates will check for pre-requisites and either prompt you to install them or install them as part of the update process.
Half of the problem is being expected to know what you need to do. At times it really does feel like there is some unspoken ritual that needs to be completed before the update will complete successfully.
Great to hear you are on your way to getting the update. 
Mod edit: Some of the following posts were moved into this topic and may therefore seem a little out of context.
hello,
my game can t upload the new file, the system do nothing. so I can t play…
my system don t want to up load a file from the store?? nothing to do…
Hello @BuyaX3150 .
Can you be more specific?
If this still doesn’t work, the best course of action is to log out, restart your computer, and log back in.
I try this, but nothing.
the game say that it need to be update, but nothing start in the store!!
I am not alone…strange. first problem since the begin…but big problem!! 
Having the same issue…windows is updated and I’ve reset app and store in cmd. I’m guessing a busy or timed server release issue. I’m Pacific coast so hopefully its just a matter of persistence.
I think too…I hope. see tomorow.
Go to the MS store, download the Xbox app, launch it then close it. Click on get updates and when it refreshes the update will be there. Worked for me and should work for you.
Saw this on another thread and it does work. Thanks!
This worked for me
Xbox app is crash too!!!?? it want to update, but it can t!!??
I win… but what a mess!!! xbox app… account to verify… a lot of problem for a lot of person!!! I don t understand…
When Microsoft Store opens up after click on the update message in the game I get nothing. Earlier I got an error message. After having the standard game since August of last year; I recently bought the premium deluxe upgrade. The MS store indicates that I own the base game but doesn’t show me owning the premium deluxe upgrade. Is this the source of the error? Why doesn’t it show ownership of premium deluxe? Any suggestions would be greatly appreciated.
The Workaround given by [DaRealGretel] Worked for me !
Many Thanks !
But as many others lot of anger towards Microsoft !!! Each upadte we have issues. Not very professional !!! I wondering who is the culprit, ASOBO, ZENDESK or Microsoft.
Thank you very much . I was totally lost and you solved my problem.
I cannot understand why microsoft is still ignoring the problem. In fact I contacted by phone looking for help and the answer was “Reinstall the whole program”
You may well need to install the Xbox app for the update to initially show in the MS Store. If you already have the app try logging out of it and back in. You may also need to close and reopen the MS Store for it to refresh and show the update for MSFS.
Please search the forum there have been lots of posts about this very problem already.
With respect to the upgrade you may need to post some more details… are you on game pass or bought the sim from the MS Store then the upgrade after?
Once you do get the sim updated and running head into the content manager to see if the additional upgrade is available to download/install.