Basic fix for Work Item 16558 - Adding too long role name causes page error. Added Data annotation to limit role name to 255 chars to avoid YSOD.

src/Orchard.Web/Modules/Orchard.Roles/ViewModels/RoleCreateViewModel.cs

@@ -4,7 +4,7 @@ using Orchard.Security.Permissions;
 
 namespace Orchard.Roles.ViewModels {
     public class RoleCreateViewModel  {
-        [Required]
+        [Required, StringLength(255)]
         public string Name { get; set; }
         public IDictionary<string, IEnumerable<Permission>> FeaturePermissions { get; set; }
     }

src/Orchard.Web/Modules/Orchard.Roles/ViewModels/RoleEditViewModel.cs

@@ -5,7 +5,7 @@ using Orchard.Security.Permissions;
 namespace Orchard.Roles.ViewModels {
     public class RoleEditViewModel  {
         public int Id { get; set; }
-        [Required]
+        [Required, StringLength(255)]
         public string Name { get; set; }
         public IDictionary<string, IEnumerable<Permission>> RoleCategoryPermissions { get; set; }
         public IEnumerable<string> CurrentPermissions { get; set; }