Update Program.cs

Author: mythz

MyApp/Program.cs

@@ -23,7 +23,7 @@
 services.ConfigureApplicationCookie(options => options.DisableRedirectsForApis());
 
 services.AddDataProtection()
-    .PersistKeysToFileSystem(new DirectoryInfo("App_Data"));
+    .PersistKeysToFileSystem(new DirectoryInfo("App_Data".AssertDir()));
 
 // Add application services.
 services.AddSingleton<IEmailSender<ApplicationUser>, IdentityNoOpEmailSender>();