Error: Synchronous operations are disallowed
Problem When you try to do a synchronous IO operation in ASP.NET Core (such as writing to a file), you get the following exception: System.InvalidOperationException: ‘Synchronous operations are disallowed. Call WriteAsync or set AllowSynchronousIO to true The reason you’re getting this is because server option AllowSynchronousIO is false. Starting in ASP.NET Core 3.0, this is … Read more