Topic
When trying to login to K2, an error page shows up with the following error message:
HTTP Error 500.19 - Internal Server Error
The requested page cannot be accessed because the related configuration data for the page is invalid.
Instructions
This is an IIS error page from IIS. IIS is reporting C:\Program Files\K2\Webservices\Identity\web.config contains a number of sections that are declared twice.
You can manually check the web.config referenced in the error page to determine if there are any sections that are declared twice, and remove the duplicate section. If you have a separate working environment, you can refer to the same web.config from the other environment to determine what is the correct value for the section.
If you are not sure, please log a support case with Nintex, and provide a screenshot of the error page and a copy of the web.config.