INVALID_WRPC_TOKEN: Validate WRPC Token: WRPCTokenState=Invalid, TOKEN_EXPIRY=4320, IGNORE_TOKEN=False, MS CRM 2011

If you are getting the below exception

Unhandled Exception: System.ServiceModel.FaultException`1[[Microsoft.Xrm.Sdk.OrganizationServiceFault, Microsoft.Xrm.Sdk, Version=5.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35]]: INVALID_WRPC_TOKEN: Validate WRPC Token: WRPCTokenState=Invalid, TOKEN_EXPIRY=4320, IGNORE_TOKEN=False, TOKEN_KEY=cqVEUanaEeCywOYfEycts16SMyCI412LpIAS+SQa9UgB+F5p6MvXmJlizmS4MUhBDetail:

-2140991221

INVALID_WRPC_TOKEN: Validate WRPC Token: WRPCTokenState=Invalid, TOKEN_EXPIRY=4320, IGNORE_TOKEN=False, TOKEN_KEY=cqVEUanaEeCywOYfEycts16SMyCI412LpIAS+SQa9UgB+F5p6MvXmJlizmS4MUhB
2011-07-15T03:04:17.945024Z

make sure that you have opened MS CRM 2011 in two different IEs and with different users. If so in browser IE8 its not supported, the user from one browser will supersid to the other.