500 Error when creating thumbnail image

Description

Steps to reproduce
1. Prepare a image with an empty blob (for example, an implementation like the following svg image).

    [ContentType(GUID = "F522B459-EB27-462C-B216-989FC7FF9448")]
    [MediaDescriptor(ExtensionString = "svg")]
    public class VectorImageFile : ImageData
    {
        public override Blob Thumbnail
        {
            get { return BinaryData; }
        }
 
        public override Blob BinaryData
        {
            get => null;
            set => base.BinaryData = value;
        }
    }

2. In Edit Mode, add an SVG image to the Asset pane.
3. Drag the image to an image property (e.g, Teaser Image in the Alloy Plan page).

Expected:
Successfully added the image to the image property. No thumbnail (or default) should be shown.

Actual: Server error 500

[NullReferenceException: Object reference not set to an instance of an object.]
   EPiServer.Cms.Shell.UI.Controllers.Internal.ThumbnailController.Generate(ContentReference contentLink) +114
   lambda_method(Closure , ControllerBase , Object[] ) +138
   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +34
   System.Web.Mvc.<>c__DisplayClass24_0.<InvokeActionMethodWithFilters>b__0() +79
   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation) +490
   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation) +490
   System.Web.Mvc.ControllerActionInvoker.InvokeAction(ControllerContext controllerContext, String actionName) +977
   System.Web.Mvc.Controller.ExecuteCore() +137
   System.Web.Mvc.ControllerBase.Execute(RequestContext requestContext) +244
   EPiServer.Shell.Web.Mvc.ModuleMvcHandler.ProcessController(IController controller) +58
   EPiServer.Shell.Web.Mvc.ModuleMvcHandler.BeginProcessRequest(HttpContextBase httpContext, AsyncCallback callback, Object state) +28
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +1128
   System.Web.HttpApplication.ExecuteStepImpl(IExecutionStep step) +220
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +134