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Using Kestrel in an ASP.NET Core Application with a Dynamic Grid


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After I upgraded kendo.all.min.js from version 2019.3.1023 to version 2020.1.114 and ASP.NET Core from 2.2 to 3.1, I have troubles with the dynamic creation of columns and data types. The functionality works on core 2.2 and doesn't work on core 3.1. No error are reported on the server or client side but the response is not rendering the Grid.


After I deleted almost everything an error occured:

    Synchronous operations are disallowed. Call WriteAsync or set AllowSynchronousIO to true instead.

It appears that .NET Core changed the defaults so you need to add the following code in Startup.cs:

    services.Configure<IISServerOptions>(options =>
        options.AllowSynchronousIO = true;

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