When I download and Import Cinemachine, I receive many errors associated with my Cinemachine imported script. However, I can start a new project with Cinemachine and run it without error.

I have to delete the whole Cinemachine folder in order to be able to run the game in the game view without error. I receive about 32 errors notifications.
How can I correct this error and use Cinemachine in my already existing project.

It’s always a good practice to delete your CM folder before importing a new one, especially if you’re coming from v1.5 to v2 or to v2.1

That should fix any issue you have. The Cinemachine forums have a release candidate for v2.1 which you can try out - it will be put on the Asset Store very shortly.

okay, I will try it, I have also received similar errors when I download and import the xbox live package