'Profiler' error message, but no Profiler code

When I deploy to iOS as a develompent build, the debug output is constantly spammed with 'Profiler is only supported in Unity Pro' every frame.

However, I've double and triple checked everything, including plugin code, and there are no calls to Profiler.Begin or anything like that.

The message does not appear when I run it in the editor. Does anyone have any idea what to do?