Hi,

Normally logging in to my customers website works great. But every now and then something happens that produces the following error for everyone that tries to log in:

[NullReferenceException: Object reference not set to an instance of an object.]
   EPiServer.Security.MultiplexingMembershipProvider.FindMembershipUser(String username) +115
   EPiServer.Security.MultiplexingMembershipProvider.get_CurrentMembershipUser() +166
   EPiServer.Security.MultiplexingMembershipProvider.get_CurrentProvider() +96
   EPiServer.Security.MultiplexingMembershipProvider.ValidateUser(String username, String password) +34
   EPiServer.Common.Web.Authorization.Multiplexing.IntegrationMultiplexingMembershipProvider.ValidateUser(String username, String password) +30
   System.Web.UI.WebControls.Login.AuthenticateUsingMembershipProvider(AuthenticateEventArgs e) +74
   System.Web.UI.WebControls.Login.AttemptLogin() +151
   System.Web.UI.WebControls.Login.OnBubbleEvent(Object source, EventArgs e) +123
   System.Web.UI.Control.RaiseBubbleEvent(Object source, EventArgs args) +69
   System.Web.UI.Page.RaisePostBackEvent(IPostBackEventHandler sourceControl, String eventArgument) +28
   System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +2980

Recycling the applicationpool makes everything allright again. Every now and then the problem comes back. It looks like this is a problem in EPiServer.dll. Does anyone know how to fix this?

Thx!