On 2 of my EX2010 CAS/HT boxes wehn I run peformance troubleshooter it is crashing out at the ExMon User Activity Analysis / RPC Activity Checks stage. Event log gives faulting application - ExTRA, faulting module MSVCR90.dll. Any thoughts? It works ok on my DR multi-role which has CAS/HT/MBX Thanks Neill

Is it exchange installed on VM ?. Its looking some isue in virtual ENV for faulting. Did you installed SP1 of 2010 ?Anil

Hi Anil, No they are CAS/HT servers on HP hardware. Yes, EX2010 SP1 with RU1. But it works ok on my DR server which is exactly the same except it also has the MBX role. Thanks Neill

Not good, but i will advise you to have a reboot and then try it.Anil

Hi NeillT, Since ExTRA is based on .NET Framework, I would suggest you reinstall the .NET Framework 3.5.1: For Windows server 2008 SP2, please install the downloadable .NET Framework package and hotfix 959209. For Windows server 2008 R2, please use Server Manager->Feature-> Remove Features. After that, please restart the Exchange server and try again. If the problem persists, please disable the Checksum offload of NIC. Local Area Connection->Properties->Configure...->AdvancedFrank Wang

Thanks Frank. Will get a change in. Neill

Hi Neill, How about your question? Any updates?Frank Wang

Hi Neill, Any updates?Frank Wang

Hi Frank, Sorry, have not had a chance to reboot either of the servers yet. Looks like it will have to wait for this weekend. :-( Neill

Hi Neill, How about your question now?Frank Wang

Hi Frank, I removed .Net on CAS 1, rebooted and reinstalled. Same problem I simply rebooted CAS 2 Same problem For the Checksum that would be IPv4 Checksum Offload? Currently set as Tx/Rx enabled. Haven't had a chance to change. Both CAS are using a team for the public interface and single NIC for the NLB incoming link / heartbeat. Why would that make a difference I am wondering? Thanks Neill

Hi Neill, I would still suggest you disable IPv4 checksum offload in you test lab first.Frank Wang