500 internal server error iis | iis internal server error 500.19

HTTP Error 500.19 - Internal Server Error

The requested page cannot be accessed because the related configuration data for the page is invalid.

Solution:
you need to enable and see detailed errors of your webconfig file.

<configuration>
    <system.web>
        <customErrors mode="Off"/>
        <compilation debug="true"/>
    </system.web>
</configuration>

OR 
Your Hosting control panel preview option Used to find out webconfig problems.


Example: