{
  "type": "Error",
  "title": "Value cannot be null. (Parameter 'source')",
  "status": 500,
  "detail": "   at System.Linq.ThrowHelper.ThrowArgumentNullException(ExceptionArgument argument)\r\n   at System.Linq.Enumerable.Contains[TSource](IEnumerable`1 source, TSource value, IEqualityComparer`1 comparer)\r\n   at Umbraco.Cms.Core.Services.ContentTypeEditing.MediaTypeEditingService.<>c__DisplayClass8_0.<GetMediaTypesForFileExtensionAsync>b__2(KeyValuePair`2 kvp)\r\n   at System.Linq.Enumerable.IEnumerableWhereSelectIterator`2.MoveNext()\r\n   at System.Collections.Generic.List`1.AddRange(IEnumerable`1 collection)\r\n   at Umbraco.Cms.Core.Services.ContentTypeEditing.MediaTypeEditingService.GetMediaTypesForFileExtensionAsync(String fileExtension, Int32 skip, Int32 take)\r\n   at Umbraco.Cms.Api.Management.Controllers.MediaType.Item.AllowedMediaTypeItemController.Item(CancellationToken cancellationToken, String fileExtension, Int32 skip, Int32 take)\r\n   at Microsoft.AspNetCore.Mvc.Infrastructure.ActionMethodExecutor.TaskOfIActionResultExecutor.Execute(ActionContext actionContext, IActionResultTypeMapper mapper, ObjectMethodExecutor executor, Object controller, Object[] arguments)\r\n   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeActionMethodAsync>g__Logged|12_1(ControllerActionInvoker invoker)\r\n   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.<InvokeNextActionFilterAsync>g__Awaited|10_0(ControllerActionInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)\r\n   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Rethrow(ActionExecutedContextSealed context)\r\n   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)\r\n   at Microsoft.AspNetCore.Mvc.Infrastructure.ControllerActionInvoker.InvokeInnerFilterAsync()\r\n--- End of stack trace from previous location ---\r\n   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeNextResourceFilter>g__Awaited|25_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)\r\n   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Rethrow(ResourceExecutedContextSealed context)\r\n   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)\r\n   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.InvokeFilterPipelineAsync()\r\n--- End of stack trace from previous location ---\r\n   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Logged|17_1(ResourceInvoker invoker)\r\n   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Logged|17_1(ResourceInvoker invoker)\r\n   at Umbraco.Cms.Web.Common.Middleware.BasicAuthenticationMiddleware.InvokeAsync(HttpContext context, RequestDelegate next)\r\n   at Microsoft.AspNetCore.Builder.UseMiddlewareExtensions.InterfaceMiddlewareBinder.<>c__DisplayClass2_0.<<CreateMiddleware>b__0>d.MoveNext()\r\n--- End of stack trace from previous location ---\r\n   at Umbraco.Cms.Api.Management.Middleware.BackOfficeExternalLoginProviderErrorMiddleware.InvokeAsync(HttpContext context, RequestDelegate next)\r\n   at Microsoft.AspNetCore.Builder.UseMiddlewareExtensions.InterfaceMiddlewareBinder.<>c__DisplayClass2_0.<<CreateMiddleware>b__0>d.MoveNext()\r\n--- End of stack trace from previous location ---\r\n   at Swashbuckle.AspNetCore.SwaggerUI.SwaggerUIMiddleware.Invoke(HttpContext httpContext)\r\n   at Swashbuckle.AspNetCore.Swagger.SwaggerMiddleware.Invoke(HttpContext httpContext, ISwaggerProvider swaggerProvider)\r\n   at Microsoft.AspNetCore.Session.SessionMiddleware.Invoke(HttpContext context)\r\n   at Microsoft.AspNetCore.Session.SessionMiddleware.Invoke(HttpContext context)\r\n   at Microsoft.AspNetCore.Localization.RequestLocalizationMiddleware.Invoke(HttpContext context)\r\n   at Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context)\r\n   at Microsoft.AspNetCore.Authentication.AuthenticationMiddleware.Invoke(HttpContext context)\r\n   at StackExchange.Profiling.MiniProfilerMiddleware.Invoke(HttpContext context) in C:\\projects\\dotnet\\src\\MiniProfiler.AspNetCore\\MiniProfilerMiddleware.cs:line 112\r\n   at Umbraco.Cms.Web.Common.Middleware.UmbracoRequestMiddleware.InvokeAsync(HttpContext context, RequestDelegate next)\r\n   at Umbraco.Cms.Web.Common.Middleware.UmbracoRequestMiddleware.InvokeAsync(HttpContext context, RequestDelegate next)\r\n   at Microsoft.AspNetCore.Builder.UseMiddlewareExtensions.InterfaceMiddlewareBinder.<>c__DisplayClass2_0.<<CreateMiddleware>b__0>d.MoveNext()\r\n--- End of stack trace from previous location ---\r\n   at Umbraco.Cms.Web.Common.Middleware.PreviewAuthenticationMiddleware.InvokeAsync(HttpContext context, RequestDelegate next)\r\n   at Microsoft.AspNetCore.Builder.UseMiddlewareExtensions.InterfaceMiddlewareBinder.<>c__DisplayClass2_0.<<CreateMiddleware>b__0>d.MoveNext()\r\n--- End of stack trace from previous location ---\r\n   at Umbraco.Cms.Web.Common.Middleware.UmbracoRequestLoggingMiddleware.InvokeAsync(HttpContext context, RequestDelegate next)\r\n   at Microsoft.AspNetCore.Builder.UseMiddlewareExtensions.InterfaceMiddlewareBinder.<>c__DisplayClass2_0.<<CreateMiddleware>b__0>d.MoveNext()\r\n--- End of stack trace from previous location ---\r\n   at Microsoft.AspNetCore.Diagnostics.ExceptionHandlerMiddlewareImpl.<Invoke>g__Awaited|10_0(ExceptionHandlerMiddlewareImpl middleware, HttpContext context, Task task)",
  "instance": "ArgumentNullException"
}