Unable to resolve class (Confluence SpaceManager etc) in Jira Script Console

[Sngy]

Hello, I was following the code of the following question, where you can add a group to a confluence space: 

https://community.atlassian.com/t5/Marketplace-Apps-Integrations/Add-Remove-group-from-space-confluence-with-script-runner/qaq-p/1036440

But I get an "unable to resolve class" error for almost all imports (see attachment).

Anyone know why?