Hi David,
Which asset caused the errors? The Circuit asset? If so, I would recommend to simply ignore the asset, watch the video and implement everything BUT that asset. Rick is going to replace it with a Timeline animation in a later video anyway.
If you already imported your project into an earlier version of Unity, I would suggest to stick with that version because loading the project with different versions increases the risk of breaking it.
Depending on the error messages you got, maybe this solution helps.