When profiling an ASP.NET web application, the following error may appear in the web browser window:

This error occurs sporadically depending on the nature of the code being run in the website process and the causes of this message can be varied. This is because the error concerns a failure by the runtime to validate Intermediate Language code at a very low-level.

One possible fix for this problem is to enable full trust for the web application.

To do this, open the web.config file in the web application's root directory and change the trust level, for instance:

<configuration>
<system.web>
        <trust level="Full"/>
...