You may sometimes receive the below error if adding a new library to an existing project. It is also a common error when running older applications originally built for IIS 6 on newer versions of IIS.
HTTP Error 500.22 – Internal Server Error
An ASP.NET setting has been detected that does not apply in Integrated managed pipeline mode.
Luckily there are a couple of easy solutions to fixing this error:
The first thing you can try is to run the Application Pool in Classic Mode. IIS6 did not have Integrated mode so running older applications in that mode will sometimes cause problems.
The other solution you can try is to make sure validateIntegratedModeConfigurationis set to false in your web.config:
<configuration> <system.webServer> <validation validateIntegratedModeConfiguration="false"/> </system.webServer> </configuration>
Have another solution? Let us know in the comments below.