Error 267 for terrain edge 3 on Mac

Hello,
I am a MAC user with unity 3.5. I have just started using the terrain management tool Terrain Edge 3. I am getting an error 267 with the fix accompanied with another error that reads:
Assets/Resources/LibNoise.Unity/Operator/Turbulence.cs(127,49): error CS1061: Type `Perlin' does not contain a definition for 'Seed' and no extension method 'Seed' of type 'Perlin' could be found (are you missing a using directive or an assembly reference?)
The screenshot of the error is attached below:

Has anyone else encountered a similar problem?
If yes please do let me know how to fix it up. I'll be waiting for your response.
Kind regards,
