An error occurred while resolving packages

[odejinmi]

I'm building a project on version 2020.1.3f1 which I imported from version 2018.1.1f1 and am getting this error An error occurred while resolving packages: Project has invalid dependencies: com.unity.ads: Version 'exclude' is invalid. Expected one of: a 'SemVer' compatible value; a value starting with 'file:'; a Git URL starting with 'git:' or 'git+', or ending with '.git'.

[ChuanXin-Unity]

It seems like there is an error with your package manifest file. You may have to go to the Unity Package Manager window (under windows/Package Manager) to update your packages.