Hi there!My environment is:DC win2003 ad1, ad2; ad1 schema master;DC win2008 ad3;server for Exchange roles win2008When I run GUI installation I got error as is in subject "Object reference not set to an instance of an object"System log of Ex server:ID 4999 desc: The description for Event ID 4999 from source MSExchange Common cannot be found. Either the component that raises this event is not installed on your local computer or the installation is corrupted. You can install or repair the component on the local computer.If the event originated on another computer, the display information had to be saved with the event.The following information was included with the event: 888E12c-RTL-AMD6408.01.0240.006ExSetupM.E.ManagementM.E.M.T.DirectoryCommon.FindAcesSystem.NullReferenceExceptiond1e108.01.0240.005Falsethe message resource is present but the message is not found in the string/message table-------------------------------------------Exchange Logs just before error:2008-11-14 11:09:13] [2] Launching sub-task '$error.Clear(); $RolePrepareSchema = $True'.[2008-11-14 11:09:13] [1] Executing '$RoleProductPlatform = "amd64"', handleError = False[2008-11-14 11:09:13] [2] Launching sub-task '$error.Clear(); $RoleProductPlatform = "amd64"'.[2008-11-14 11:09:13] [1] Found 165 tasks to execute[2008-11-14 11:09:13] [1] Processing component 'Legacy Global AD Configuration' (Preparing the legacy forest.).[2008-11-14 11:09:13] [1] Executing 'if ($RoleDomain -ne $null) { initialize-ExchangeLegacyPermissions -Domain $RoleDomain -DomainController $RoleDomainController; } else { initialize-ExchangeLegacyPermissions -AllDomainstrue -DomainController $RoleDomainController; }', handleError = False[2008-11-14 11:09:13] [2] Launching sub-task '$error.Clear(); if ($RoleDomain -ne $null) { initialize-ExchangeLegacyPermissions -Domain $RoleDomain -DomainController $RoleDomainController; } else { initialize-ExchangeLegacyPermissions -AllDomainstrue -DomainController $RoleDomainController; }'.[2008-11-14 11:09:13] [2] Beginning processing.[2008-11-14 11:09:13] [2] Used domain controller AD1.mydomain.com to read object DC=mydomain,DC=com[2008-11-14 11:09:13] [2] Could not find the Organization Container.[2008-11-14 11:09:13] [2] Used domain controller AD1.mydomain.com to read object CN=AdminSDHolder,CN=System,DC=mydomain,DC=com[2008-11-14 11:09:13] [2] [WARNING] An unexpected error has occurred and debug information is being generated: Object reference not set to an instance of an object.[2008-11-14 11:09:13] [2] [ERROR] Object reference not set to an instance of an object.[2008-11-14 11:09:13] [1] Exception : System.Management.Automation.CmdletInvocationException: Object reference not set to an instance of an object. ---> System.NullReferenceException: Object reference not set to an instance of an object. at Microsoft.Exchange.Management.Tasks.DirectoryCommon.FindAces(ADObject obj, ActiveDirectoryAccessRule[] aces) at Microsoft.Exchange.Management.Tasks.InitializeExchangeLegacyPermissions.IsDomainSetupNeeded(ADObjectId domainId) at Microsoft.Exchange.Management.Tasks.DomainSetupTaskBase.InternalValidate() at Microsoft.Exchange.Configuration.Tasks.Task.ProcessRecord() at System.Management.Automation.Cmdlet.DoProcessRecord() at System.Management.Automation.CommandProcessor.ProcessRecord() --- End of inner exception stack trace --- at System.Management.Automation.Internal.PipelineProcessor.SynchronousExecuteEnumerate(Object input, Hashtable errorResults, Boolean enumerate) at System.Management.Automation.Parser.PipelineNode.Execute(Array input, Pipe outputPipe, ArrayList& resultList) at System.Management.Automation.Parser.StatementListNode.Execute(Array input, Pipe outputPipe, ArrayList& resultList)[2008-11-14 11:09:14] [1] [WARNING] An unexpected error has occurred and debug information is being generated: Object reference not set to an instance of an object.[2008-11-14 11:09:14] [1] [ERROR] Object reference not set to an instance of an object.[2008-11-14 11:09:14] [1] [ERROR] Object reference not set to an instance of an object.[2008-11-14 11:09:14] [1] [ERROR] Object reference not set to an instance of an object.[2008-11-14 11:09:14] [1] [ERROR] Object reference not set to an instance of an object.---------------------------------------In this environment was someday installed Exchange 2007 but uninstalled with no errors (that was done by other people)Please Help.

Hi, Please remove Exchange Domain Servers and Exchange Enterprise Servers security group from Active Directory Users & Computers. After the installation complete, please apply the latest update. Update Rollup 4 for Exchange Server 2007 Service Pack 1 (KB952580) Update Rollup 4 for Exchange Server 2007 SP1 has been released http://msexchangeteam.com/archive/2008/10/07/449931.aspx Similar thread for your reference: Problem with install Exchange 2007(event 4999) Hope it helps. Xiu

Event ID 4999 has a lot of causes and it would be easier to find out if there were other error events from Exchange.Here it was only one.As I saw only I had such error (other similiar were with .NET objects).After deleteing Exchange Domain Servers and Exchange Enterprise Servers, installation proceed OK.Thanks a lot. I knew it is something simply to do.

Hi I also have the same issue with the same error. But Exchange 2007 Infra does not have above mention Groups. In my case i am getting Event Type: Error Event Source: Microsoft Exchange Server Event Category: None Event ID: 5000 Date: 1/4/2010 Time: 10:23:57 PM Computer: HOEXCH-MB-N2 Description: The description for Event ID ( 5000 ) in Source ( Microsoft Exchange Server ) cannot be found. The local computer may not have the necessary registry information or message DLL files to display messages from a remote computer. You may be able to use the /AUXSOURCE= flag to retrieve this description; see Help and Support for details. The following information is part of the event: e12, c-rtl-amd64, 08.01.0240.006, exsetupui, m.e.c.replay, m.e.c.c.group.isclustergroup, system.nullreferenceexception, bdbc, 08.01.0240.005, NIL, NIL. Data: 0000: 65 00 31 00 32 00 2c 00 e.1.2.,. 0008: 20 00 63 00 2d 00 72 00 .c.-.r. 0010: 74 00 6c 00 2d 00 61 00 t.l.-.a. 0018: 6d 00 64 00 36 00 34 00 m.d.6.4. 0020: 2c 00 20 00 30 00 38 00 ,. .0.8. 0028: 2e 00 30 00 31 00 2e 00 ..0.1... 0030: 30 00 32 00 34 00 30 00 0.2.4.0. 0038: 2e 00 30 00 30 00 36 00 ..0.0.6. 0040: 2c 00 20 00 65 00 78 00 ,. .e.x. 0048: 73 00 65 00 74 00 75 00 s.e.t.u. 0050: 70 00 75 00 69 00 2c 00 p.u.i.,. 0058: 20 00 6d 00 2e 00 65 00 .m...e. 0060: 2e 00 63 00 2e 00 72 00 ..c...r. 0068: 65 00 70 00 6c 00 61 00 e.p.l.a. 0070: 79 00 2c 00 20 00 6d 00 y.,. .m. 0078: 2e 00 65 00 2e 00 63 00 ..e...c. 0080: 2e 00 63 00 2e 00 67 00 ..c...g. 0088: 72 00 6f 00 75 00 70 00 r.o.u.p. 0090: 2e 00 69 00 73 00 63 00 ..i.s.c. 0098: 6c 00 75 00 73 00 74 00 l.u.s.t. 00a0: 65 00 72 00 67 00 72 00 e.r.g.r. 00a8: 6f 00 75 00 70 00 2c 00 o.u.p.,. 00b0: 20 00 73 00 79 00 73 00 .s.y.s. 00b8: 74 00 65 00 6d 00 2e 00 t.e.m... 00c0: 6e 00 75 00 6c 00 6c 00 n.u.l.l. 00c8: 72 00 65 00 66 00 65 00 r.e.f.e. 00d0: 72 00 65 00 6e 00 63 00 r.e.n.c. 00d8: 65 00 65 00 78 00 63 00 e.e.x.c. 00e0: 65 00 70 00 74 00 69 00 e.p.t.i. 00e8: 6f 00 6e 00 2c 00 20 00 o.n.,. . 00f0: 62 00 64 00 62 00 63 00 b.d.b.c. 00f8: 2c 00 20 00 30 00 38 00 ,. .0.8. 0100: 2e 00 30 00 31 00 2e 00 ..0.1... 0108: 30 00 32 00 34 00 30 00 0.2.4.0. 0110: 2e 00 30 00 30 00 35 00 ..0.0.5. 0118: 2c 00 20 00 4e 00 49 00 ,. .N.I. 0120: 4c 00 20 00 4e 00 49 00 L. .N.I. 0128: 4c 00 0d 00 0a 00 L..... Event Type: Error Event Source: MSExchange Common Event Category: Devices Event ID: 4999 Date: 1/4/2010 Time: 10:23:46 PM Computer: HOEXCH-MB-N2 Description: The description for Event ID ( 4999 ) in Source ( MSExchange Common ) cannot be found. The local computer may not have the necessary registry information or message DLL files to display messages from a remote computer. You may be able to use the /AUXSOURCE= flag to retrieve this description; see Help and Support for details. The following information is part of the event: 3516, E12, c-RTL-AMD64, 08.01.0240.006, exsetupui, M.E.C.Replay, M.E.C.C.Group.IsClusterGroup, System.NullReferenceException, bdbc, 08.01.0240.005, True.