The original plugin was developed for SketchUp 2015–2018. The developer, TIG, discontinued active updates several years ago. However, a community-managed version exists called which works reliably up to SketchUp 2023.

(Note: Do not copy-paste from unreliable third-party sites – type this directly or search "SketchUcation Slicer 5").

Go to the official SketchUcation plugin page using this address: https://sketchucation.com/pluginstore?plon=slicer5