SUMMARY It seams that graphviz is not included in the snap package. I (together with Ralf Habacker) noticed that because the auto layout function did not work. Umbrello installed from snap package: sudo snap install umbrello Kubuntu 18.04 x64 For more information see Bug 411207
A possibly relevant merge request was started @ https://invent.kde.org/sdk/umbrello/-/merge_requests/42
Git commit fd100aef468ba8cd68f42f91b47ee6043ec82d06 by Joshua Goins, on behalf of Scarlett Moore. Committed on 16/11/2023 at 18:31. Pushed by redstrate into branch 'release/23.08'. snapcraft: Fix runtime issues. Add graphvis dep. M +2 -0 snapcraft.yaml https://invent.kde.org/sdk/umbrello/-/commit/fd100aef468ba8cd68f42f91b47ee6043ec82d06