Error "Could not reconnect to the server. Reload the page to restore functionality." in ASP.NET Core Blazor Server

Question

Error "Could not reconnect to the server. Reload the page to restore functionality." in ASP.NET Core Blazor Server

v38armageddon ‫ 61

Hello,

I have a ASP.NET Core Blazor Server website, self hosted in a Linux machine (Fedora) with NGINX for Cloudflare.

On my published website, after a certain moment, a error show: "Could not reconnect to the server. Reload the page to restore functionality.". When I click on "Reload", it goes back to the main page.

When my website is launched in Visual Studio 2022, the problem is not appearing.

Do you know how I can resolve this bug?

Thanks.

Anonymous

2022-11-30T05:47:47.783+00:00

Hi @v38armageddon-0698,

> On my published website, after a certain moment, a error show: "Could not reconnect to the server. Reload the page to restore functionality.". When I click on "Reload", it goes back to the main page. > > When my website is launched in Visual Studio 2022, the problem is not appearing.

Generally, this error happens when the connection id on the server is not found. this implies you are using blazor server, and the server blazor instance for the connection is not found. maybe the server recycled, crashed or the affinity cookie is not correctly configured. Since this website works well in VS 2022 and local machine, and it will show this error in Linux (Fedora), I think you'd better to contact with them (Fedora), perhaps the issue relates the NGINX or Linux(Fedora) setting.
v38armageddon ‫ 61 Reputation points

2022-12-01T11:39:33.477+00:00

Will try, I let know in a update if my problem is resolved or not and how ti resolve it (in case of another user have the same problem).
Daniel M 0 Reputation points

2023-08-17T14:07:19.6466667+00:00

Any updates on that question?

I have the exact same problem with the same nginx/cloudflare setup

1 answer

Your answer

Anonymous

2022-11-30T05:47:47.783+00:00

Hi @v38armageddon-0698,

> On my published website, after a certain moment, a error show: "Could not reconnect to the server. Reload the page to restore functionality.". When I click on "Reload", it goes back to the main page. > > When my website is launched in Visual Studio 2022, the problem is not appearing.

Generally, this error happens when the connection id on the server is not found. this implies you are using blazor server, and the server blazor instance for the connection is not found. maybe the server recycled, crashed or the affinity cookie is not correctly configured. Since this website works well in VS 2022 and local machine, and it will show this error in Linux (Fedora), I think you'd better to contact with them (Fedora), perhaps the issue relates the NGINX or Linux(Fedora) setting.
v38armageddon ‫ 61 Reputation points

2022-12-01T11:39:33.477+00:00

Will try, I let know in a update if my problem is resolved or not and how ti resolve it (in case of another user have the same problem).
Daniel M 0 Reputation points

2023-08-17T14:07:19.6466667+00:00

Any updates on that question?

I have the exact same problem with the same nginx/cloudflare setup

Answer 1

Bruce (SqlWork.com) 78,006 Volunteer Moderator

Blazor requires a persistent web socket connection. If the connection is lost, the client has about 90 seconds to reconnect. Cloudflare is aggressive on closing web socket connections, typically 100 seconds of inactivity.

To keep the connection open you may need a "ping". Have the client run a timer and send a message to the server every 60 seconds.

Another issue that browsers are gettin more aggressive at closing web socket connections. if the tab becomes inactive (not current visible tab), the browser may close the connection.

Mobile devices will often lose connectivity long enough to kill a blazor server connections.

the default reconnect logic to restart the app. you can add persistent state management, and better recovery.

Daniel M 0 Reputation points

2023-08-21T08:36:32.69+00:00

Thanks for the answer. But then it looks to me like the technology behind Blazor with the SignalR connections is just not good for hosting a website with it. Is there a reasonable default configuration for this to improve the connection issue?

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Error "Could not reconnect to the server. Reload the page to restore functionality." in ASP.NET Core Blazor Server

1 answer

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