Hi @mumi32, and welcome to the forum. Thank you for posting regarding your experience with Joulescope UI 0.9.3 and macOS. Yes, Joulescope UI 0.9.3 was built using macOS Big Sur, which for some reason (Apple) is no longer compatible with macOS 10, including Catalina. If you are still running Catalina, you should stay with Joulescope 0.9.2.
We are considering how difficult it will be to support macOS 10 going forward. Do you have plans to upgrade to macOS 11 Big Sur in the near future?
An alternative is to run from the Python packages. See this post.