An issue can occur when a user clicks on the New system menu button to create a DotNet custom entity in CRM 7.2.
When the new button is clicked an IIS error page is displayed
"403 error trying to browse a folder."
1. Use the advanced customisation wizard in component manager to create an new DotNet entity and add the entity to the new & Find menus.
2. (Right Click) New Custom Entity.
3. (Right Click) Go to Find the Entity.
4. (Left Click) Go to New.
5. (Left Click) Go to Find.
6. (Left Click) Go to New.
The 403.19 error will be displayed