Blazor Web Server default template does not run in Firefox in Visual Studio Community. insertBefore error. #63062
Description
This issue has been moved from a ticket on Developer Community.
[severity:Other]
Steps
-
Create a new Blazor Web Server project. Take default options. No extra pages included so that you have just the Home page.
-
On the 'https' button click the dropdown arrow. Make sure the specified browser is Firefox.
-
Click on Run (i.e., the https button.
What Happens
The page appears to display perfectly. However, at the bottom appears the message:
>An unhandled error has occurred. Reload.
In my real Blazor project, the user interface is frozen. The navigation menu does not work. You cannot navigate to other pages of the Blazor Web Server app.
Firefox Version: 140.0.4 (64-bit)
I will try to attach
- A screenshot of the Firefox browser after pressing F12 (shows errors)
- A zipfile of the PowerShell Window Contents (shows errors)
- A zipfile of the project
What I hope Microsoft will do
This problem looks to me like a Firefox problem. But the question is, is there anything practical that Microsoft can do to accommodate how Firefox works. If so, I hope Microsoft will implement a solution. Regardless of whether Blazor Web Server can accommodate Firefox, if it is a Firefox problem, notify Firefox to give Firefox (Mozilla) the information they need to fix their browser.
Concluding Statement
I believe Blazor Web Server wants to run with all the popular browsers, including Firefox. And I believe Firefox wants to work with all the popular web applications and websites, including Blazor Web Server. I hope this submission will be helpful. Let me know if I might be able to provide any additional useful information about this.
Original Comments
Feedback Bot on 7/16/2025, 03:51 AM:
We have directed your feedback to the appropriate engineering team for further evaluation. The team will review the feedback and notify you about the next steps.