1 Answer, 1 is accepted
Hi Marc,
Thank you for share the console errors:
Access to fetch at "http://localhost:60028/?code=4C22C6278928C86FBDF435C1D86B42D6DCF2BD6BF613A25DBD286429F8EDAD75&fed=null&error=null&error_description=null" from origin 'https://www.telerik.com' has been blocked by CORS policy: The request to access the 'unknown' address space.
Uncaught (in promise) TypeError: Failed to fetch at browser-auth
We are aware of similar issues that can occur when Local Network Access is not permitted in Chrome.
When this permission is disabled, the browser may fail to load the Control Panel app, which can interrupt the login process.
Additionally, Microsoft has confirmed that the Windows 11 cumulative update KB5066835 (October 2025) can interfere with localhost communication in certain cases. You can find more details here: https://learn.microsoft.com/en-us/answers/questions/5585563/localhost-not-working-anymore-after-2025-10-cumula
In the meantime, please try the following steps:- Enable Local Network Access in Chrome
- Temporarily disable any firewall, antivirus, or endpoint protection tools and attempt login again.
- If possible, try a different browser (such as Microsoft Edge).
- Check whether the Windows update KB5066835 is installed. If it is, uninstalling it may help restore localhost connectivity.
Please let us know if any of these steps resolve the issue or if it persists after testing.
Best Regards,
Misho
Progress Telerik
Rank 2
Bronze
Iron
Iron
Hi Misho,
Your first pointer did the trick, thank you.
Marc