Today I came across an issue where the customer is getting “The object identifier does not represent a valid object. (Exception from HRESULT: 0x800710D8)” when you try to start the Web site.

Looking at the IIS Manager, the Web site status shows:

Looking closer, found the Web site identifier is set to 0.

This is not a valid identifier. Tried “net start WAS” this stopped W3SVC as well. Now, ran the command “net start W3SVC”. Checked the System Event log and we see:

Checked ApplicationPool in IIS Manager, and we don't see DefaultAppPool.

Looking at the applicationHost.config:

<applicationPools>
   <add name="Classic .NET AppPool" managedPipelineMode="Classic" />
   <applicationPoolDefaults>
      <processModel identityType="ApplicationPoolIdentity" />
   </applicationPoolDefaults>
</applicationPools>

Created the DefaultAppPool and now the applicationHost.config looks good:

<applicationPools>
   <add name="DefaultAppPool" />
   <add name="Classic .NET AppPool" managedPipelineMode="Classic" />
   <applicationPoolDefaults>
      <processModel identityType="ApplicationPoolIdentity" />
   </applicationPoolDefaults>
</applicationPools>

Hit Refresh (F5) in the IIS Manager. The Default Web Site is now started. Remember to change the Default Web Site ID from 0 to 1, as that will give you some "Server Application Unavailable" error as well.

Happy troubleshooting,
Vivek Kumbhar

Quote of the day:
If you are not criticized, you may not be doing much. - Donald H. Rumsfeld