Browser POST error # 429 (Too Many Requests) when attempting to login to a website

Question

Hi, I recently purchased a new laptop (Dell) and have had it for less than 48 hours. I haven't really even had a chance to customize it nor install any applications other than alternate browsers (Chrome and Firefox). This PC is mostly for browsing the web and nothing else.

Windows is up-to-date to latest version available at this time:

Edition Windows 11 Home

Version 25H2

Installed on ‎12/‎14/‎2025

OS build 26200.7462

Experience Windows Feature Experience Pack 1000.26100.275.0

The problem that I'm having is not being able to successfully login to a website (ancestry.com) that I can easily access from other PCs, including mobile devices. The credentials are correct, so that's not the issue (I also had a different user try their credentials on the same computer with the exact same results as I'll outline below).

When I click the "Sign In" the button displays a spinning icon which is normal for a second or two and would indicate that the system is processing the credentials before eventually taking the user to the next screen. However, this icon just spins and never progresses beyond this point. So I started to look at the browser's developer options (F12) to see what was going on. The browser is reporting a pre-authentication error # 429 (Too Many Requests). It just shows this message over and over again until I close the page.

The exact message shows the following:

Failed to load resource: the server responded with a status of 429 () https://www.ancestry.com/account/signin/api/pre-authenticate
request-header-overrides.js:1 POST https://www.ancestry.com/account/signin/api/pre-authenticate 429 (Too Many Requests)

Even though the Sign In button is only pressed a single time, the system seems to think the request was sent multiple times, over and over.

Here is some of the additional troubleshooting steps that I've tried:

1. Tried multiple browsers: Microsoft Edge, Google Chrome and Mozilla Firefox and saw the exact same results on all 3 browsers.
2. Tried accessing the site in Incognito Modes on all 3 browsers.
3. Cleared the cache on each browser.
4. Made sure no weren't any browser extensions installed.
5. Uninstalled 3rd party security suite software (anti-virus and firewall).
6. Tried accessing the site after booting the computer to safe mode with networking to eliminate the possibility of some other background software interfering with the browser request.
7. Tried using a different ISP connection (I have two ISPs that I can statically set a computer to use)
8. Viewed Windows Event Viewer for any system or application logs that would suggest a potential issue.
9. Tried using a VPN, but that didn't have an impact either.
10. I contacted Ancestry.com to see if they would have any ideas as to what causing this issue, but their stance is that since the issue is isolated to this specific PC then that would suggest the problem is local and not server-side.

My original thought was the problem is on the server side, however, other devices on the same network can successfully login using the same credentials. This leads me to believe that there isn't anything wrong with the user account itself nor the ISP where the connection is coming from. It's also worth pointing out that I can successfully login to other frequently used websites without issue. So far it's just this one particular website and it's only happening on this PC. The problem also is happening for multiple user accounts that can normally access this website.

Any ideas as to what may be causing this issue on this specific PC that is about as close to its out-of-box state as can be without refreshing/reinstalling Windows?

Thanks in advance!

Answer 1

As a last ditch effort, I reinstalled Windows from scratch to reset it back to factory defaults. This did not resolve the issue. I contacted Ancestry.com again and their stance is that since things work on other devices that the issue is completely isolated to this one and I'm inclined to agree with them. This computer is a CoPilot enabled device. Could any of those AI features be having an impact on this issue?

Answer 2

Just want to mention that I was able to figure out what was causing this issue. The culprit was a pre-installed application from Dell called "Dell Optimizer". From what I can tell, this app consists of a collection of apps and services that shipped with the computer. Reinstalling Windows simply reinstalled the app. Manually uninstalling Dell Optimizer allowed each browser to successfully login to ancestry.com without the errors that mentioned earlier. I'm not sure what hooks this app has into the OS, but it was causing this particular issue. Hopefully, this helps someone else if they run into to this or a similar issue.

Answer 3

The error message you're encountering, "429 (Too Many Requests)", typically indicates that the server is receiving too many requests from your client in a short period. This can happen for several reasons, especially if the server is interpreting your attempts to log in as multiple requests. Here are some troubleshooting steps you can consider:

1. Clear Cookies: Since the error can occur due to a large number of cookies being sent in the request headers, try clearing cookies specifically for the site you're trying to access. This can help reduce the size of the request header.
2. Check for Background Processes: Ensure that there are no background processes or applications that might be making repeated requests to the server. Sometimes, security software or browser extensions can interfere and cause multiple requests.
3. Network Configuration: Since you mentioned trying different ISPs, ensure that there are no network configurations or firewalls that might be affecting the connection to the specific website.
4. Browser Settings: Double-check that your browser settings are not blocking any necessary scripts or cookies that the site requires for authentication.
5. Temporary IP Block: It's possible that your IP address has been temporarily blocked by the website due to perceived excessive requests. If you have access to a different network, try logging in from there.
6. Contact Support: Since you've already reached out to Ancestry.com, consider asking them if they can provide any logs or insights on why your requests are being flagged as excessive.

If the issue persists after trying these steps, it may be worth considering a complete reset of your network settings or even reinstalling the browsers to ensure there are no lingering issues.

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References:

• "Header Field Too Long" error when accessing a SharePoint Online site
• A federated user is repeatedly prompted for credentials during sign-in to Microsoft 365, Azure or Intune