Thank you for kindly responding so quickly. I have indeed done everything that you said including setting the appropriate sql provider, however, I still received that same error message.
So what I have had to do for now so that I can use the sql membership and role providers is to simply comment out the following lines:
<add name="XmlMembershipProvider" type="BlogEngine.Core.Providers.XmlMembershipProvider, BlogEngine.Core" description="XML membership provider" passwordFormat="Hashed"/>
<add name="XmlRoleProvider" type="BlogEngine.Core.Providers.XmlRoleProvider, BlogEngine.Core" description="XML role provider"/>
As a result the aforementioned error is no longer displayed when I run the Website Admin Tool and click on the Security tab. However, I then realised that the
Website Admin Tool and the Users section of the BlogEngine.Net admin area was showing that I had 0 members/users in my existing ASP Membership tables which I know is not true. So after scouring the web I learned that I had to
share the applicationname in the BlogEngine.Net web.config file with the
applicationname in my existing MVC 3 Web Application's web.config file and ensure that the Application ID is the same for each user in the Membership tables and linked to the same
applicationname. After doing that I can now use the ASP.Net Website Admin Tool and BlogEngine.Net admin area to view and mange all of the roles and users that were created by my existing MVC 3 Web Application. I can
seperately log in to BlogEngine.Net using those members/users credentials.
The problem that I am having now is that if I log into my existing MVC 3 Web Application, BlogEngine still prompts me to log in again when I try to access
the admin area. I need to be able to log in to my existing MVC web application and then for BlogEngine.Net to somehow recognise that I am already logged in using one of the users/members in the ASP Membership tables that my two web application share.
For what it's worth I am using the standard authentication code in my existing MVC 3 Web Application:
if (Membership.ValidateUser(model.UserName, model.Password))
Any help or guidance would be much appreciated.