HTTP Error 404. The requested resource is not found.
Hello people, i'm face some trouble when i try to connect my Blazor Server to a .NET API running in a Windows Server.
It just loads and returns to me something like that:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN""http://www.w3.org/TR/html4/strict.dtd">
<HTML><HEAD><TITLE>Not Found</TITLE>
<META HTTP-EQUIV="Content-Type" Content="text/html; charset=us-ascii"></HEAD>
<BODY><h2>Not Found</h2>
<hr><p>HTTP Error 404. The requested resource is not found.</p>
</BODY></HTML>
When i look at the console on the browser, it shows me that message:
blazor.web.js:1 [2025-08-04T19:20:16.466Z] Error: Error: Failed to complete negotiation with the server: Error: <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN""http://www.w3.org/TR/html4/strict.dtd">
<HTML><HEAD><TITLE>Not Found</TITLE>
<META HTTP-EQUIV="Content-Type" Content="text/html; charset=us-ascii"></HEAD>
<BODY><h2>Not Found</h2>
<hr><p>HTTP Error 404. The requested resource is not found.</p>
</BODY></HTML>
: Status code '404' Either this is not a SignalR endpoint or there is a proxy blocking the connection.
I already try to redeploy the app, reset the proxy configs but nothing works. Someone already faced something like that and can help me?
It just loads and returns to me something like that:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN""http://www.w3.org/TR/html4/strict.dtd">
<HTML><HEAD><TITLE>Not Found</TITLE>
<META HTTP-EQUIV="Content-Type" Content="text/html; charset=us-ascii"></HEAD>
<BODY><h2>Not Found</h2>
<hr><p>HTTP Error 404. The requested resource is not found.</p>
</BODY></HTML>
When i look at the console on the browser, it shows me that message:
blazor.web.js:1 [2025-08-04T19:20:16.466Z] Error: Error: Failed to complete negotiation with the server: Error: <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN""http://www.w3.org/TR/html4/strict.dtd">
<HTML><HEAD><TITLE>Not Found</TITLE>
<META HTTP-EQUIV="Content-Type" Content="text/html; charset=us-ascii"></HEAD>
<BODY><h2>Not Found</h2>
<hr><p>HTTP Error 404. The requested resource is not found.</p>
</BODY></HTML>
: Status code '404' Either this is not a SignalR endpoint or there is a proxy blocking the connection.
I already try to redeploy the app, reset the proxy configs but nothing works. Someone already faced something like that and can help me?
