title: How do I fix DNN registration NullReferenceException on ProfilePropertyAccess.DisplayDataType?
body: <p>On our production environment users are unable to register.</p>
  
  <p>They receive: <code>An error has occurred. Error: User Registration is currently unavailable.</code></p>
  
  <p>The stacktrace is:</p>
  
  <p>DotNetNuke.Services.Exceptions.ModuleLoadException: Object reference not set to an instance of an object. ---> System.NullReferenceException: Object reference not set to an instance of an object. at DotNetNuke.Entities.Users.ProfilePropertyAccess.DisplayDataType(ProfilePropertyDefinition definition) at DotNetNuke.Entities.Users.ProfilePropertyAccess.GetRichValue(ProfilePropertyDefinition prop, String strFormat, CultureInfo formatProvider) at DotNetNuke.Entities.Users.ProfilePropertyAccess.GetProperty(String strPropertyName, String strFormat, CultureInfo formatProvider, UserInfo AccessingUser, Scope currentScope, Boolean&amp; PropertyNotFound) at DotNetNuke.Services.Tokens.BaseCustomTokenReplace.replacedTokenValue(String strObjectName, String strPropertyName, String strFormat) at DotNetNuke.Services.Tokens.BaseTokenReplace.ReplaceTokens(String strSourceText) at DotNetNuke.Services.Localization.Localization.GetSystemMessage(String strLanguage, PortalSettings objPortal, String MessageName, UserInfo objUser, String ResourceFile, ArrayList CustomArray, IDictionary CustomDictionary, String CustomCaption, Int32 AccessingUserID) at DotNetNuke.Services.Mail.Mail.SendMail(UserInfo user, MessageType msgType, PortalSettings settings) at DotNetNuke.Entities.Modules.UserModuleBase.CompleteUserCreation(UserCreateStatus createStatus, UserInfo newUser, Boolean notify, Boolean register) at DotNetNuke.Modules.Admin.Users.ManageUsers.UserCreateCompleted(Object sender, UserCreatedEventArgs e)</p>
  
  <p>I suspect there is a profile property definition missing. I'm wondering how to fix this error?</p>