All, I am running Virtualbox 6.1.36 PUEL version (I need the USB). It has run fine for years and years (since version 3.X). Today I went to start it and it would not load. Starting from the command line as my user, I get: VirtualBox Qt FATAL: FATAL: The application binary appears to be running setuid, this is a security hole. Aborted Huh? WTF? Obviously it is unhappy with Qt or vice versa. This worked fine a couple of weeks ago. What to check to narrow down the issue? I can su and then VirtualBox runs, but since it is running under root, none of my VM's are found. Running with sudo -E I receive: No protocol specified No protocol specified Qt CRITICAL: This application failed to start because no Qt platform plugin could be initialized. Reinstalling the application may fix this problem. Available platform plugins are: eglfs, linuxfb, minimal, minimalegl, offscreen, vnc, xcb. Now running su'ed to root, Virtualbox starts and the dialog appears, but no vms are shown. The following warning is shown on the command line: Qt WARNING: QStandardPaths: runtime directory '/run/user/1000' is not owned by UID 0, but a directory permissions 0700 owned by UID 1000 GID 1060 What has changed with Qt these past two weeks that is causing VirtualBox to freak out? -- David C. Rankin, J.D.,P.E.