Hi All,. I am using SCCM 2007 SP2 R2 on Windows 2003 SP2 Standard edition x64 box.SCCM is in Mixed mode.I am trying to extend the date of self signed PXE certificate in ConfigMgr PXE service point role properties.When I extend the date and say Apply, I am getting the below error message. mmc has detected an error in a snap-in and will uload it. Unable to find assembly 'AdminUI.WqlQueryEngine, Version=4.0.6000.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35'. Server stack trace: at System.Runtime.Serialization.Formatters.Binary.BinaryAssemblyInfo.GetAssembly() at System.Runtime.Serialization.Formatters.Binary.ObjectReader.GetType(BinaryAssemblyInfo assemblyInfo, String name) at System.Runtime.Serialization.Formatters.Binary.ObjectMap..ctor(String objectName, String[] memberNames, BinaryTypeEnum[] binaryTypeEnumA, Object[] typeInformationA, Int32[] memberAssemIds, ObjectReader objectReader, Int32 objectId, BinaryAssemblyInfo assemblyInfo, SizedArray assemIdToAssemblyTable) at System.Runtime.Serialization.Formatters.Binary.__BinaryParser.ReadObjectWithMapTyped(BinaryObjectWithMapTyped record) at System.Runtime.Serialization.Formatters.Binary.__BinaryParser.Run() at System.Runtime.Serialization.Formatters.Binary.ObjectReader.Deserialize(HeaderHandler handler, __BinaryParser serParser, Boolean fCheck, Boolean isCrossAppDomain, IMethodCallMessage methodCallMessage) at System.Runtime.Serialization.Formatters.Binary.BinaryFormatter.Deserialize(Stream serializationStream, HeaderHandler handler, Boolean fCheck, Boolean isCrossAppDomain, IMethodCallMessage methodCallMessage) at System.Runtime.Remoting.Channels.CrossAppDomainSerializer.DeserializeObject(MemoryStream stm) at System.Runtime.Remoting.Messaging.SmuggledMethodReturnMessage.FixupForNewAppDomain() at System.Runtime.Remoting.Channels.CrossAppDomainSink.SyncProcessMessage(IMessage reqMsg) Exception rethrown at [0]: at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg) at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type) at Microsoft.ManagementConsole.Internal.IMessageClient.ProcessRequest(Request request) at Microsoft.ManagementConsole.Executive.RequestStatus.BeginRequest(IMessageClient messageClient, RequestInfo requestInfo) at Microsoft.ManagementConsole.Executive.SnapInRequestOperation.ProcessRequest() at Microsoft.ManagementConsole.Executive.Operation.OnThreadTransfer(SimpleOperationCallback callback) Note - When the same process is done with one of my colleague account, it happens fine and he is able to extend the self signed PXE expiration date.As per the setting in our environment PXE's serive point computer account is used to connect with the database. Question - Why this is happening successfully with my colleagues account and not happening when I am using my account.We both have same permission in AD and aswell as in SCCM for all the instances. Thanks & Regards Deepak Kumar