Another IIS Profiler Detected

Issue

The .NET agent doesn't start, and the following error message is displayed in the Tray application:

> The Contrast .NET service cannot start with another profiler attached
  to IIS. COR_ENABLE_PROFILING: 0x01, COR_PROFILER:
  {BX7CFC47-3E35-2c2e-B495-534F93B28123}, COR_PROFILER_PATH:...

Cause

The CLR Profiling API only allows a single agent to be attached to a .NET process. The Contrast .NET agent uses the Profiling API to perform data/code flow analysis and detect libraries used by the application.

Note: Many performance/APM tools - such as New Relic, AppDynamics and Dynatrace - also use the CLR Profiling API.

Resolution

To resolve the issue, the Contrast .NET Framework agent implements "profiler chaining" that allows it to run side-by-side with another profiling tool. To enable chaining, add the following to your contrast_security.yaml file:

agent:
  dotnet:
    enable_chaining: true