When profiling an application containing an assembly compiled into an NGen Profile image, profiling may fail with the error :

Method not found: 'UInt32 <Module>._ANTS_Begin_Sql(System.String)'

This error is caused by a bug in the .NET profiling API, whereby the profiler loads the NGen profile image at runtime but cannot instrument it. NGen profile images are created by tools such as BugAid, including for .NET framework assemblies, in order to improve application performance.

To enable profiling if this message has appeared, do one of the following:

• At the command prompt, enter ngen uninstall * /profile and start a new profiling session.

  This removes the NGen profile images and allows the profiler to instrument the application.

• Start a new profiling session in sampling mode.

  This prevents ANTS Performance Profiler from attempting to instrument the application, and avoids loading the NGen profile image.