value does not fall within the expected range

Custom IIS App Pool Identity: Value does not fall within the expected range

Export private key on good machine via command prompt:

C:\Windows\Microsoft.NET\Framework64\v4.0.30319>aspnet_regiis -px "iisWasKey" "C:\temp\AESKeys.xml" -pri

Import on broken machine via command prompt:

C:\Windows\Microsoft.NET\Framework64\v4.0.30319>aspnet_regiis -pi "iisWasKey" "C:\temp\AESKeys.xml"

Then make sure to use the block of code from good server to use on the bad so they match:

   <configProtectedData>

       <providers>

           <add name=........

           <add name=........

       </providers>

   </configProtectedData>

net stop was /y

net start w3svc