We have recently detected an issue with the Guitar Lab app and macOS 10.13 High Sierra. The Guitar Lab app does not work properly on macOS High Sierra which is slated to be released on September 26, 2017.
If you are currently using the Guitar Lab app, we recommend that you do not update to macOS High Sierra for the time being.
Please check back for updates on this issue. We apologize for any inconvenience.
About Zoom North America:
Zoom North America is the U.S. affiliate of the Zoom Corporation (Japan). The company prides itself on offering its customers the very highest level of service and support.