What Studio version are you using?
Try to use the Stable version of the UiPath.Excel.Activities package and try to lower (downgrade) the version as I think is not compatible with your actual Studio version.
Try first to upgrade all dependencies to the latest version in the project.
Close Studio.
Go to the folder where the packages are downloaded → %userprofile%\.nuget and rename the packages folder to packages_backup.
Reopen the Main.xaml or project.json in UiPath Studio.