"Entry has already been added" - Two Separate App Pools
application-pool, asp.net-mvc-4
Solution
Web.config inheritance happens even between different appPools. If you want to stop this behavior, you should add the attribute `enableConfigurationOverride="false"` to your appPool in the applicationHost.config file (located in %WINDIR%\System32\inetsrv\Config and %WINDIR%\SysWOW64\inetsrv\config) as in the following example:
<add name="MyAppPool" autoStart="true" managedRuntimeVersion="v4.0" managedPipelineMode="Integrated" enableConfigurationOverride="false">
<processModel identityType="NetworkService" />
</add>
Matteo
Problem
I am creating a test version of an existing production site. A virtual web service application exists inside the site - and the two web configs have the same connection string. There are no "clear" tags in the production web configs and the site and the web service co-exist merrily on two separate app pools. On the test site however, every time I browse to the webservice URL I receive the Configuration Error "The entry 'ConnectionString' has already been added." The test site and corresponding virtual application use their own separate app pools. Any ideas? Thanks Jim