You will want to pull the Logs files off the ESX server and see if there are any errors before the core dump that could give light into which module if failing on the ESX server.

How can I do that?.  Do you any manuals or documents with this?

thanks for your response.

Well, this is an EMC forum so I guess we can cover VMWare here.   I am assuming you have Virtual Center for this.  Connect to the Virtual Center using the virtual center client and go to the Administration menu and choose Export System Logs.  Choose the ESX host you want the data from.  UNCHECK to include data from vCenter Server or vSphere client.  Save the logs.  This can take a while.

Note:  I usually execute the command or problem that gives me the error right before exporting the logs so it is near the end of the logs and you don't have to read through them all.

Once the logs are downloaded, extract the zip and look through them for any errors around the time you executed.

Ted

I'm so sorry for that. thank you for your help.