After upgrading to ASP.NET Core 2.1 (.NET Core SDK 2.1.301), you may encounter the following error about encoding:
System.ArgumentException HResult=0x80070057 Message='Cyrillic' is not a supported encoding name. For information on defining a custom encoding, see the documentation for the Encoding.RegisterProvider method. Source=System.Private.CoreLib StackTrace: at System.Text.EncodingTable.internalGetCodePageFromName(String name) at System.Text.EncodingTable.GetCodePageFromName(String name) at System.Text.Encoding.GetEncoding(String name)
The error message itself already provides the solution.
To resolve the issue, add package reference System.Text.Encoding.CodePages.
And then register code page encoding provider via Encoding.RegisterProvider method.
public void ConfigureServices(IServiceCollection services) {// …// Register code Encoding.RegisterProvider(CodePagesEncodingProvider.Instance);}