Do you have any add-ons in your Community folder? No Are you using Developer Mode or made changes in it?` No
Brief description of the issue:
Crashes when clicking on the App Icon after 2 seconds
PC specs for those who want to assist (if not entered in your profile)
Build Version # when you first started experiencing this issue:
Are you on the Steam or Microsoft Store version? MS Store
Check Windowsā Event Viewer, to see what causes the crashā¦ Search for Event Viewer in Windows.
Start > Windows Administrative Tools > Event Viewer
In the left pane, click āWindows Logsā, select āApplicationā and in the list in the centre pane look for an error log filed at the time of the crash.
For example it might look something starting out like this:
Faulting application name: FlightSimulator.exe, version: 0.0.0.0, time stamp: 0x00000000
Faulting module name: AudioDevProps2.dll, version: 2.6.4.0ā¦
My fix was with Audio Drivers, and in particular Sonic Studio. Uninstalling Sonic Studio fixed my issue of crashing at startup. It mightnāt be that for you, but if people see the faulting module name they may be able to help more.
I allready uninstalled Sonic Studio
Log Name: Application
Source: Application Error
Date: 7/30/2021 8:51:51 PM
Event ID: 1000
Task Category: (100)
Level: Error
Keywords: Classic
User: N/A
Computer: MichaGaming
Description:
Faulting application name: FlightSimulator.exe, version: 0.0.0.0, time stamp: 0x00000000
Faulting module name: ucrtbase.dll, version: 10.0.19041.789, time stamp: 0x2bd748bf
Exception code: 0xc0000409
Fault offset: 0x000000000007286e
Faulting process id: 0x3968
Faulting application start time: 0x01d78573ddf03422
Faulting application path: C:\Program Files\WindowsApps\Microsoft.FlightSimulator_1.18.14.0_x64__8wekyb3d8bbwe\FlightSimulator.exe
Faulting module path: C:\WINDOWS\System32\ucrtbase.dll
Report Id: 8902e2d6-d511-4b5f-b05e-c784a2928393
Faulting package full name: Microsoft.FlightSimulator_1.18.14.0_x64__8wekyb3d8bbwe
Faulting package-relative application ID: App
Event Xml:
1000
0
2
100
0
0x80000000000000
5414
Application
MichaGaming
FlightSimulator.exe
0.0.0.0
00000000
ucrtbase.dll
10.0.19041.789
2bd748bf
c0000409
000000000007286e
3968
01d78573ddf03422
C:\Program Files\WindowsApps\Microsoft.FlightSimulator_1.18.14.0_x64__8wekyb3d8bbwe\FlightSimulator.exe
C:\WINDOWS\System32\ucrtbase.dll
8902e2d6-d511-4b5f-b05e-c784a2928393
Microsoft.FlightSimulator_1.18.14.0_x64__8wekyb3d8bbwe
App
Exact same issue, have you been able to launch the game ?
You mean with " exact same issue " the error " 0xc0000409 ucrtbase.dll " ?
We mentioned a lot of times the possible reasons for that. What you already tried from the given hints ?
( from missing US lang pack, till sound drivers )
Yeah, same error code and same behaviour.
Iāve spent quite some time trying fixes yesterday, including US lang pack, disabling unnecessary programs on windows start, of course updating windows, all my drivers and such, also reinstalling .net, and vc redists, I even tried holding the mouse click button as Iāve seen someone mentioning that helped with the issues for some reason so thatās as far as I went, to no avail. Iām considering the prayer as the only option atm.
the important thing are the sound tools/drivers and the Nahimic service.
You tried this ?
and donāt forget the Windows Restart ( not only shutdown and start, choose restart )
I found out, that my Bullguard Firewall was/ is in the way.
Everytime I restart the PC I have to Block Flightsim in my firewall settings and release it after that.
This works fine.
a lolā¦ yepā¦ this is the third case which can cause the " 0xc0000409 ucrtbase.dll "
funnily I summarized it today here:
Thanks for trying to help my situation btw.
I have no audio software layer, besides the vanilla āAudio Windowsā service. Iām using a hardware DAC with non-gaming headphones. I highly doubt it comes from that. I tried unplugging the device and running MSFS though just to give it a try but it didnāt work.
Iāve tried the US Lang pack as default with any other lang pack uninstalled, and a reboot of course.
I have no antivirus besides Windows Defender. I excluded the MSFS folder in Windows Defender. Also tried running MSFS with Windows Defender Firewall disabled.
to be sure that it is not sound related you can
note: itās not necessary to make it to default. Important is only the installtion of it ( US ).
Ƥhmmā¦ Have you VR hardware ?
EDIT: and I forgotā¦ some audio drivers are auto-installed, depend on mainboard. I remember one case for a MSI mainbaord user. May be double check that no Nahimc service exist ( If already done, ignore my sentence 
)
Iāve tried disablind Audio Windows service, I can confirm I had no sound haha. MSFS still crashed.
Iāve alwasys had US Lang pack installed (as secondary lang pack), Iāve just tried to run the game once with the pack used as default but yeah, didnāt work.
I donāt have any VR hardware or VR related services.
I own a msi motherboard but I donāt have the Nahimic drivers installed. Otherwise Iām pretty sure I would have got ridden of it when I installed my current PC, since Iām producing audio a general rule of thumb is get rid of anything sound related so the signal is as pure as possible. Thatās why I highly doubt it comes from my audio setting. Just to be sure Iāve checked if I had any sound-related service installed but looks like I have none.
it is installed in background 
( these was the MSI thread : Game Crashes at Launch - #29 by MichaMMA )
I have also not basic audio setting, also some Asio drivers etcā¦ have no issues.
The only special thing I have is, that I not have installed the nvidias audio HD drivers ( disabled while install )ā¦ May beā¦
So iāve checked pretty much everywhere to see if I had that Nahimic thing going on, canāt find it in my services, device manager, task manager or system32. If itās install on my PC itās really well hidden indeed.
Iāve tried reinstalling anything audio related I had on my PC in the last 30 minutes (which was not much tbh) but MSFS is still crashing.
Iām really thankful for your help but Iām ready to give up now. Iāve spent like 15hrs in the last couple days to get this game working. I know weāre dealing with Microsoft here but come on it shouldnāt be that painful to start a game you paid for. I submitted a Zendesk ticket, I donāt expect much from it but at least Iām a +1 in the list of complaints about the last update making the game crash. Hope theyāll fix it soon but for now I think Iāll just pass.
Thanks again though
only in services
May be we should then search another reason for the issue.
The only idea for now is a simple re-login. But in case that will work, we need a drink 
Ahā¦ and just in these momentā¦ have you Steam ? I remember situations where users with Steam account and xbox gamepass ( making these relation is more a guess) had trouble to play the game in case they are online. We assumed a account issue.
PS: and with +1 you mean the Vote Button ? ā¦ Users just Vote in forum if they run into the same issue and so it can proirized for the developers. Its nothing personal or nothing like a āLikeā. That does not mean that the Support should let you alone or that the community ignore your issue.
Iām in the same trouble, i donāt understantā¦ this fu**ing update 5 broke the game .
I have VR is it the problem may be ?
I tried to relog with different strategies to no avail. I do own a steam account but Iām only using Microsoft Store for MSFS.
For Zendesk, I just meant +1 ticket, these end up as numbers and I do believe it counts when the marketing dept checks the support stats to see that to be able to deploy their game on Xbox, they had tons of bugs & issues reported by unsatisfied customers on PC, and budget cuts on testing before releasing aināt a solution. Iām very glad the community here help each other but I donāt think it should be up to the community to help the others about launching the game. And so far, Iāve only had bot answers from the support. Thatās not something they should take lightly, the real issue here is addressing a trust issue with their customer base because clearly Iām not buying an other game published by Microsoft or released on their platform anymore, and I donāt think Iām the only one.
Well I checked out your profile real quick and I assume youāve been through a lot since youāre playing Arma 3 and other simulators, and so did I. Itās been like 15 years since Iāve encountered an issue that harsh with a game, one of the kind that would prevent me from playing it, and investing so much time in fixing the bug by myself (and the help of people over the internet though). Itās unrreal for me. Iāve known Microsoft UX to be ā ā ā ā ā ā for quite a while but being as ā ā ā ā ā ā as it is now, I mean to that extent, in 2021, makes me speechless. Itās like they havenāt learned a thing from the past years.
I wish you the best though mate, it really means a lot to find a stranger wishing to help even if he has nothing to gain from that
Same issue here. No sound drivers, using MOTU M4 interface for sound. Nothing in community folder. Completely stock, vanilla game. Will not boot.
Description: I the game starts. Black screen, white loading circle. White loading circle stops. Check task manager. Task manager says Flight Simulator has stopped responding. Must try to start game around 7-12 times before it will eventually start. Most of the time will CTD within 20 minutes of play time.
What Iāve Tried:
remove anything pertaining to sound, including interface.
Modified .exe file to have -fastflag modifcation.
Set exe file administrator. Launch from safe mode.
Use DDU to remove all aspects of GPU drivers - reinstalled drivers.
Disabled VPN.
Disabled all security.
Reinstalled to OS drive.
Reinstalled back to game drive.
Ensured thermals were good.
Ran memtest86.
Stress test GPU
Test PCIe slots
Test CPU
Hardware
2080ti, 8700k, 32gb 3200mhz ram m.2 game drive. m.2 os drive.
NO errors in application log
This issue isnāt from the recent update but has been ongoing and progressively getting worse since about 3 or 4 updates ago.
Game is through steam. No xbox or microsoft game apps. All windows game apps are turned off, if not removed.
hmmmā¦ noticed the heading ? Canāt open the Game after hot fix
The hotfix 11d ago : Su5 1.18.xxx
You not see a log message in windows event viewer, because āhas stopped respondingā is not a CTD.
I recommend to search in forum about issues related to āstopped respondingā and in case you not find an existing topic where you can join, create a new issue. ( I have currently not much about in mind, as the usually reasons from login-issues, OC , hardware issues ( in special in case I see you can sometime fly ), conflicting apps, mods, etcā¦ )
you are not wrong, but you can see in forum that these issue seems rare. And if we, the community, have currently nothing in mind about, hmmmmā¦ But I thought there is a escalation of the ticket possible, in case you can no longer fly. At least support can check the account for a possible issue.
My last hope was the Nvidia HD audio driversā¦ and may be also check in Geforce Exp. that Auot-Optimize is disabled. All other things you tried already, like c++ reinstall.
To try ā-FastLaunchā param, as mentioned from @Skyking20205069 , is also a test worth. We had realy cases where the game died because of showing the intro video ( but canāt remember the error message ).
oh yes ā¦ but in my case I must say I had till now no big issues with MSFS. The first patch after release was a bit pain, but since that it works. There are bugs (oh yes) , but nothing what prevent me to fly.