Hi,
Cubase LE 5 is not compatible with macOS 10.13 (High Sierra).
However, I really wonder why many of you still using outdated Versions of Cubase LE/AI on modern operating systems since we offer free updates to the latest Cubase LE/AI Version.
https://helpcenter.steinberg.de/hc/en-us/articles/360011791099-FAQ-Free-update-to-latest-Cubase-AI-Cubase-LE-version-for-all-registered-users
Cheers,
Jochen