Child Item

The Dropbox desktop app won't start or sync on Windows 11

Application Affected
Dropbox

Operating System/Browser (if using the web)
Windows 11
Dropbox App Version (if using the app)
App won't launch but i have installed the latest version

Question or Issue
I noticed that Dropbox was no longer syncing my photos and files from my PC. Saw that the System Tray icon was gray and when I clicked is just said starting. I followed some other troubleshooting steps like uninstall and reinstall, removing old users (there's just me), restarting, etc. I even tried clearing the cache folder.

When I start the app, it takes me through connecting and the startup options and connects to my account. At the end of this process I get the error "Couldn't start Dropbox"

The text of the second link is :

bn.BUILD_KEY: Dropbox bn.VERSION: 237.4.5655 bn.constants.WINDOWS_SHELL_EXT_VERSION: 88 bn.is_frozen: True machine_id: 32b5fdfb-d178-4a0f-bcb0-eccb1b7070bb pid: 37392 cwd: 'C:\\Program Files (x86)\\Dropbox\\Client' real_path='C:\\Program Files (x86)\\Dropbox\\Client' mode=0o40777 uid=0 gid=0 parent mode=0o40777 uid=0 gid=0 HOME: None appdata: 'C:\\Users\\Owner\\AppData\\Local\\Dropbox\\instance2' real_path='C:\\Users\\Owner\\AppData\\Local\\Dropbox\\instance2' mode=0o40777 uid=0 gid=0 parent mode=0o40777 uid=0 gid=0 dropbox_path: None not found parent not found sys_executable: 'C:\\Program Files (x86)\\Dropbox\\Client\\Dropbox.exe' real_path='C:\\Program Files (x86)\\Dropbox\\Client\\Dropbox.exe' mode=0o100777 uid=0 gid=0 parent mode=0o40777 uid=0 gid=0 trace.__file__: 'C:\\Program Files (x86)\\Dropbox\\Client\\237.4.5655\\python-packages.zip\\dropbox\\client\\ui\\common\\boot_error.pyc' real_path='C:\\Program Files (x86)\\Dropbox\\Client\\237.4.5655\\python-packages.zip\\dropbox\\client\\ui\\common\\boot_error.pyc' not found parent not found TMP: C:\Users\Owner\AppData\Local\Temp TEMP: C:\Users\Owner\AppData\Local\Temp tempdir: 'C:\\Users\\Owner\\AppData\\Local\\Temp' real_path='C:\\Users\\Owner\\AppData\\Local\\Temp' mode=0o40777 uid=0 gid=0 parent mode=0o40777 uid=0 gid=0 Traceback (most recent call last): File "desktop/dropbox/client/main.py", line 6857, in _setup_root_for_account File "desktop/dropbox/sync_root/helpers.py", line 199, in create_root_for_account File "desktop/dropbox/foundation/futures/basic.py", line 1044, in result File "desktop/dropbox/sync_root/manager.py", line 382, in create_root File "desktop/dropbox/sync_root/handlers/windows/cloud_files.py", line 299, in register File "desktop/dropbox/sync_root/handlers/windows/cloud_files.py", line 601, in _register OSError: [WinError -2147024501] Access to the cloud file is denied

I don't use the cloud back feature at all. This just started happening about a week ago.

Any Ideas. The files are there and I can access through explorer, but they are not syncing. Sync is working from my Android phone for photos etc. but they are not syncing back to my desktop.

Thanks

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EastyT

Well, it took a week of thrashing around, but support eventually came up with the answer. This entire issue had to do with a Dropbox update to make it compatible with Microsoft's new sync API called Cloud Files The solution was to unlink my desktop from the Dropbox dashboard, uninstall, reboot, reinstall. Then during the welcome process at the end choose advanced setting Check the Opt Out checkbox under Dropbox for Windows Updates.

That's it, it all works now.

Thanks for everyone trying to help solve this issue. It seems that Dropbox is aware of the issue, it just took some time to find the right support rep that was aware of it.

Thanks Again!

All comments

Walter

Hey @EastyT - sorry to hear about this.

Have you tried reinstalling the app since you first noticed this error? If you did and this persists, you can try an advanced reinstall as well.

Let me know how it goes!

EastyT

Yes, I have uninstalled and reinstalled twice, I have cleared the cache folder. I try to run the desktop app and it goes through the initial setup and then errors out with the message I provided above.

I read the advanced reinstall document and though I am pretty technical, it confuses me. It makes a couple of references to running or quitting the desktop app, neither of which works. I would like to make not of my current settings/preferences before this procedure but I'm not quite sure how to find them. This has worked very well for many years. Now, I'm at a loss.

Walter

You should be able to find your settings in the app's preferences and take a screenshot if needed @EastyT.

As for the reinstall process, give it a go and let us know if you stumble upon a specific step or action and we'll take it from there.

If you happen to have a security program, like an antivirus etc., you can also temporarily disable them.

Let me know how you get on anyhow!

EastyT

Well, I have followed the directions precisely, uninstalled, deleted the client folder, made the change in the registry, restarted and reinstalled. The installation process went smoothly and logged into my existing account. Same as before, the Dropbox app appears in the task bar but is greyed out just saying it starting. I was able to right click the greyed out icon and click the settings icon and then preferences. The only two choices available in settings are General and Network. In General it offers a language choice and that's it. In Network it offers Custom Proxy Settings which is turned off. Still, the app just says starting. I can see the Dropbox shortcut on my desktop and I can access the files and folders.

All of the files in my Camera Uploads folder have the circular Sync icon next to the title and say Sync Pending but the files are accessible via my desktop folder as well as the Dropbox Desktop in Chrome. There are several photos that were taken over the past 2 weeks that show a blank icon, no sync icon and are not accessible. I can copy things using the web interface and they upload to Dropbox but copying to the Dropbox folder does not as I'm sure that's where the syncing comes in.

I'm sure you've already seen this in my first post, as I included an error log of some sort. The last line in the log speaks of "[WinError -2147024501] Access to the cloud file is denied". This may not be related at all and there is plenty more stuff in the log file. I really don't know where to go from here. It seems that app has installed properly but is stuck in "Starting" mode.

WRiedel

Maybe check Windows event log. Windows Logs, System, and look for Source: Schannel and A fatal error occurred while creating a TLS client credential. The internal error state is 10011.
The SSPI client process is Dropbox (PID: xxxxx).
If that's the case your TLS restrictions are to secure for Dropbox ;-)

Jay

Hi @EastyT, do you have any proxy, VPN, firewall, or even ISP/router settings that could be restricting traffic to the following Dropbox domains?

EastyT

i checked the System log and there are no errors that reference TLS or Dropbox. I checked the Application log and found one, but I don't think it is what you are looking for:

Log Name: Application
Source: SideBySide
Date: 11/22/2025 10:09:45 AM
Event ID: 33
Task Category: None
Level: Error
Keywords: Classic
User: N/A
Description:
Activation context generation failed for "C:\Program Files (x86)\Dropbox\Client\Dropbox.exe". Dependent Assembly 237.4.5655,language="*",type="win32",version="901.520.64.112" could not be found. Please use sxstrace.exe for detailed diagnosis.

When I go to the preferences tab (about all that's available while "starting up", it does have an option to sign in. When I do this, it says I'm already signed in under this account. Is there a way to sign out on this computer and force the app to sign in itself?

EastyT

Hi, No, I don't have any proxy, VPN. I certainly use Windows Firewall and the Firewall on my router. I checked apps allowed through and Dropbox is whitelisted. This has been working for years and I have not changed any security configurations.

EastyT

I went to the Web based preferences under security and logged out my PC. The logged in listing went away and the app in the systray immediately popped a window for me to log in. I did this and it went through a couple of questions about syncing and then popped and error dialog box that say "Couldn't start Dropbox" with some links saying to contact support with relevant information that I posted in my first message. Essentially it seems that there is some trouble with:

.
.
Traceback (most recent call last): File "desktop/dropbox/client/main.py", line 6857, in _setup_root_for_account File "desktop/dropbox/sync_root/helpers.py", line 199, in create_root_for_account File "desktop/dropbox/foundation/futures/basic.py", line 1044, in result File "desktop/dropbox/sync_root/manager.py", line 382, in create_root File "desktop/dropbox/sync_root/handlers/windows/cloud_files.py", line 299, in register File "desktop/dropbox/sync_root/handlers/windows/cloud_files.py", line 601, in _register OSError: [WinError -2147024501] Access to the cloud file is denied

Hannah

Hey @EastyT, thanks for the additional info.

I just sent you an email, so we can investigate this further internally.

See you there!

EastyT

I'm looking forward to a solution, but the Holiday and switching to Dropbox support has slowed things down.

Hannah

We really appreciate your patience, @EastyT.

I can see that our team is working on your issue, so hopefully they'll have an update for you really soon.

Let us know if you need anything else.

EastyT

That's it, it all works now.

Thanks for everyone trying to help solve this issue. It seems that Dropbox is aware of the issue, it just took some time to find the right support rep that was aware of it.

Thanks Again!

Megan

Hey @EastyT, thanks for letting us know about this!

Happy to see that your issue is now resolved! If you need something else, please let me know and I will be more than happy to help every step of the way.

Wishing you a wonderful week ahead! 😇

Theresa

Hi there @EastyT, and thanks for reaching out to us in the Dropbox Community! 😊

I am glad to see your issue is resolved - desktop app startup or sync problems on Windows 11 can be especially frustrating, so it’s great to hear things are running properly again. These glitches can have a few different causes, so thank you for taking the time to come back and share what worked. Updates like yours are super helpful for anyone who might encounter the same issue!

By the way, I’m Theresa 👩‍💻, one of the community managers here at Dropbox HQ. Since you’ve been working through this on the desktop app, I’d love to know: what’s your favorite Dropbox feature? Whether it’s Smart Sync, Backup, sharing tools, or something totally different, I’m always curious what people enjoy most about using Dropbox day-to-day.

Looking forward to hearing more,

T 😺 (Dropbox Community Manager)