As stated here http://msdn.microsoft.com/en-us/library/system.web.security.membershipprovider.onvalidatingpassword.aspx
"When the ValidatingPassword event has completed, the properties of the ValidatePasswordEventArgs object supplied as the e parameter can be examined to determine whether the current action should be canceled and if a particular Exception, stored in the FailureInformation property, should be thrown."
Here is some details/code which really shows why FailureInformation could be null http://forums.asp.net/t/991002.aspx
According with my Membership settings i should get an exception that password does not match password security conditions, but it is not happened.
Then i did try to debug System.Web.ApplicationServices.dll(in .NET 4.0 System.Web.Security located here) Framework Code to see whats really happens there, but i cant step into this assembly, may be because of this [TypeForwardedFrom("System.Web, Version=2.0.0.0, Culture=Neutral, PublicKeyToken=b03f5f7f11d50a3a")]
public abstract class MembershipProvider : ProviderBase
Easily i may step into any another .NET 4.0 assembly, but in this one not. I did check, symbols for System.Web.ApplicationServices.dll loaded.
Now i have only one idea how ti fix it - to override method OnValidatingPassword(ValidatePasswordEventArgs e).
Thats my story.
May be some one may help:
1) Any ideas why OnValidatingPassword not working?
2) Any ideas how to step into it?