Editing a file field might fail with an error when you click Open file in the Experience Editor.
The following error can be found in the logs:
Exception: System.ArgumentNullException Message: Value cannot be null. Parameter name: name Source: Sitecore.Kernel at Sitecore.Diagnostics.Assert.ArgumentNotNull(Object argument, String argumentName) at Sitecore.Globalization.Language.Parse(String name) at Sitecore.Shell.Applications.ContentEditor.File.OpenFile(ClientPipelineArgs args)
To resolve the issue, consider one of the following options: