Marianne,
 
The access control plugin structure has changed slightly in MPNews 5, so your existing plugin will no longer work, as mentioned in the upgrade utility.
 
If you try to recompile your code against the new MPNews assemblies you will find the aspects that need changing. The main points are:
  • Role-based security has now been made explicit in the IAccessControlProvider interface. Instead of each IPrincipal returning a list of permissions applicable to that user, the provider returns a list of role names from the new GetAllowedRoles method that are allowed to access a requested newsgroup.
  • Users returned from the GetPrincipalsFromConnection method must now implement the standard System.Security.Principal.IPrincipal interface, so that MPNews can check whether they are assigned to any of the allowed roles returned from the earlier method.
  • New methods GetPrincipalsFromEmail and GetPrincipalsFromUsername must be implemented in the provider.
I'm moving this topic to the mps.mpnews.customization newsgroup - please direct any replies to that newsgroup.
 
Mark