Symptoms
You may receive the following error attempting to log on to a SharePoint 2007 site: An unexpected error has occurred (AD FS 2.0 - "An unexpected error has occurred" Error or Blank Page Displayed Attempting to Log on to SharePoint, Event ID 23 Logged)
On SharePoint 2010, no error will be displayed and instead you will see a blank page in the browser
If you enable AD FS 2.0 tracing, you will see Event ID 23 logged at the same time as the logon failure.
Log Name: AD FS 2.0 Tracing/Debug Source: AD FS 2.0 Tracing Date: 8/6/2010 1:54:41 PM Event ID: 23 Task Category: None Level: Warning Keywords: ADFSAttributeStore User: CONTOSO\adfssrvc Computer: CONTOSOSRV01.contoso.com Description: LDAPAttributeStoreReader: Attribute value for claimType
http://schemas.microsoft.com/ws/2007/08/ldap/mail is not found in attribute cache Event Xml: <Event
xmlns="http://schemas.microsoft.com/win/2004/08/events/event"> <System> <Provider
Name="AD FS 2.0 Tracing"
Guid="{f1aa12b3-dba2-4cab-b909-2c2b7afcf1fd}"
/> <EventID>23</EventID> <Version>0</Version> <Level>3</Level> <Task>0</Task> <Opcode>0</Opcode> <Keywords>0x8000000000000010</Keywords> <TimeCreated
SystemTime="2010-08-06T17:54:41.257599200Z"
/> <EventRecordID>74</EventRecordID> <Correlation
ActivityID="{79EA24E7-B808-4650-B864-CAF862DA3067}"
/> <Execution
ProcessID="3748"
ThreadID="3420"
ProcessorID="0"
KernelTime="2"
UserTime="13"
/> <Channel>AD FS 2.0 Tracing/Debug</Channel> <Computer>CONTOSOSRV01.contoso.com</Computer> <Security
UserID="S-1-5-21-3424507853-4201969778-1758407596-1107"
/> </System> <UserData> <Event
xmlns:auto-ns2="http://schemas.microsoft.com/win/2004/08/events"
xmlns="http://schemas.microsoft.com/ActiveDirectoryFederationServices/2.0/Events"> <EventData>LDAPAttributeStoreReader:
Attribute value for claimType
http://schemas.microsoft.com/ws/2007/08/ldap/mail is not found in attribute cache</EventData> </Event> </UserData> </Event>