iTween error even with demo

I just installed Unity 4.2.1f4 and installed the itween from the asset shop. As per the instructions, I created a folder under Assets called Plugins. I then moved the itween.cs file into my new Plugins folder. I load the demo scene, but it won’t run. “All Compiler Errors have to be fixed before you can enter the playmode”. Other than moving the itween.cs file, I have made no changes.

Is there something else that needs to be done to install this? a dll or something?

FYI: If I create a new project and select iTween to import from the start it works. How do I import it into an existing project?

Fixed: I needed to compile the script in the mono Develop script editor. After that everything worked.

Thanks,
Tony

If you look in the Console you can see the compiler errors, which will give you a better of idea of what’s wrong.

Since it works in a fresh project, one possibility is that you already have an older version of iTween in your project.