IIS 8: Custom app pool ID: Value does not fall within the expected range

Question

I have a pair of IIS 8 machines, both with identical app hosts, both with precisely the same machine keys. On one of them, when I try to use a custom account for my application pool id, everything works hunky-dory. On the other, when I attempt to do this, I close the dialogue box to enter the password, leaving me at the advanced settings dialogue box. When I close that, I receive an error stating "Value does not fall within the expected range."

I've tried everything I can possibly think of here: I've copy and pasted the app host from the working machine to the non-working. Exported and imported machine keys. Looked at every configuration that I can think of and banged against it with a hammer - all to no avail.

If anyone has any idea what could be going on or what further steps I could take to try to diagnose this I'd greatly appreciate it.

Thanks!

Answer 1

Following steps fixed the issue for me after wasting 4 hours. I am on Windows 10 Pro but the steps are probably same in versions:

1. Uninstall IIS completely (from Control Panel Turn Windows features on or off)
2. Uninstall Windows Process Activation Service (from Control Panel Turn Windows features on or off)
3. Restart
4. Make sure %windir%\system32\inetsrv\ is now clean (I also deleted my config files so if you need to back them up do that first)
5. Reinstall items in 1 & 2
6. Verify you can now save App Pool custom identity. You can open %windir%\System32\inetsrv\config\applicationHost.config to see custom identity and password is saved (password is encrypted)

<add name="<APPPOOLNAME>">
    <processModel identityType="SpecificUser" userName="<USERNAME>" password="[enc:IISWASOnlyAesProvider:CCn5MVIrWZ/sxeGXrXfHniMSL3NoOn8SLvKiaaRfz7c=:enc]" />
</add>