I get Package restore failed. Rolling back package changes for \'ConsoleApp1\' while installing a new package. In particular I am trying to install the dropbox
The problem was that I am using Console App(.Net Core) Core is not compatible with Dropbox API.
I figured that out by opening NuGet Package Manager -> Package Manager Console and running Install-Package Dropbox-Api.
Then the error message about compatibility was on the screen plain to see.
To solve the problem I am switching to Console App (.Net Framework).