Reading that post it sounds like they’ve fixed the WU9 download so it is safe to use for those who already reset the sim, and are working on a code patch to allow users who have not reset then sim to recover without any loss.
I’m in the first group, having already reset the reserved space and installed only non-WU content.
The fix they are working on will make it so an .exe update will occur for the whole sim and take you out of the crash loop some users are stuck in, so they will not have to delete their Reserved Space.
Thanks for updating us, I appreciate that.
Hopefully the fix comes soon and is a smooth one. Glad the team is working hard to correct this issue. I’m sure it’s not fun for them either.
Cheers
I also do not believe it to be fun for them because they would not like to fail in what ever manner. Bugs do happen and at least we get action quickly.
Non Xbox user.
Do you have the same issue if you follow the OP’s steps to reproduce it?
yes, CTD everytime on starting the sim
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CTD happens while the sim is loading after the “checking for updates” screen
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Do you have the same issue if you follow the OP’s steps to reproduce it?
yes
Provide extra information to complete the original description of the issue:
If relevant, provide additional screenshots/video:
I don’t understand this…. Xbox ultimate…
I have ownership the msfs2020 premium deluxe edition, but when I look in the ms store, I have nothing….
Before was im Besitz Status… now I can buy!
Im also Xbox ultimate User!
I hope you’re guys become this fixed 
And I can’t any delete file… when I stuck in !!!
Do you have the same issue if you follow the OP’s steps to reproduce it?
YES
Provide extra information to complete the original description of the issue:
All flights delayed! 
The game wont load the main MSFS menu at all, it just crashes to the desktop. I have included a quick video. Please note it did NOT do this after the initial WU Italy install.
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Do you have the same issue if you follow the OP’s steps to reproduce it?
Yes
Provide extra information to complete the original description of the issue:
Xbox Series S
Have not installed the latest WU9. Am running 1.25.9.0
Was able to load up and play for several hours last night. Tonight I got six straight CTDs. Game boots up, shows studio logos and checking installed content, then shows new WU9 screens, then immediately crashes.
Tried both with my VelocityOne plugged and unplugged. Same results.
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I haven’t started the sim since before WU9 was available. This announcement seems to be saying the server-side fix should make it safe for me to run MSFS and download WU9 without encountering the crashes other Xbox users have seen, but I think I’ll just wait until a general fix is available. I don’t need the aggravation if it doesn’t work.
Its ok to start up - the download is an optional one so simply ignore it. I was on yesterday and it was working pretty well, i just have not downloaded WU9
Obvious question, but i musk ask: Why is it that some users are so heavily affected, and others have no problems at all,again, on a closed system like Xbox 
. Same hardware, same software etc…
Well, unfortunately, it’s not that simple. Same software? only conditionally. There are different editions of MSFS. In addition, there are X combinations of add-ons and hardware used.
Still crashing for me on cloud gaming this morning, with no way to clear any data, I can’t even make it to the main menu.
Not sure if the fix has been pushed to the cloud service yet?
Do you have the same issue if you follow the OP’s steps to reproduce it?
Yes
Provide extra information to complete the original description of the issue:
I have the XBOX Series X. Updated to SU9 and worked fine, but after updating to World Update IX, MSFS would not start and kept quitting at around 70% (startup progress bar). Will there be an update or should I spend time to delete and reinstall MSFS 2020?
Looks like many other users with XBOX are having this same issue. Please HELP! Thank You.
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Have you read this yet?
There is a way to clear data. However, doing so will:
• Remove all downloaded content — Deluxe & Premium content, WUs, add-ons purchased from the Marketplace — Any of which will need to be re-downloaded
• Clear Bush Trip progress
• Clear Rolling Cache & reset its settings
• Reset Data settings
• Reset Traffic Slider settings
• Clear Custom Camera Views
The process:
• Quit the sim via: Xbox Home Button—>Highlight FS2020–>Press menu—>Select Quit
• Clear Reserved Space via: Xbox Home Button—>Highlight FS2020–>Press Menu—>Select Manage game and add-ons—>Saved data—>Reserved Space—>Clear Reserved Space
I don’t have an Xbox I’m only streaming this game on the cloud service!
So if anything in save data is corrupted/causing further crashes, I can do nothing about it
I could install it on my PC but I doubt it would run
Gah! I’ve got no idea how the cloud service works.
I was able to stop the crashing by removing the Bijan Seasons. Must be conflicting with something.
LouP