Thank you for reporting this!
The notice you are seeing regarding the profiler and pro license pertains to a setting you have configured in Unity and is unrelated to the missing method error you received.
Please see this page for tips on how you may be able to get the profiler message to go away:
Regarding the missing method error, if you select the error can you retrieve and send the full stack trace to me?
In the meantime, you can set your project to the .NET 2.0 profile since that method may not be available on 2.0 subset, micro, or webplayer profiles. See API compatibility level: