An AppImage that reports a FUSE error has reached a different problem from a text script opening in an editor. Keep the exact message and the publisher's download details before changing Ubuntu packages. A launch failure is not a reason to run the whole application as root.

Match the application and Ubuntu release

Confirm that the AppImage came from the intended publisher and was built for your machine's architecture. Record the Ubuntu release and the AppImage version. The AppImage project notes that a build intended for another platform can produce a similar FUSE message, so the wording alone does not prove which package is missing.

FUSE is the filesystem mechanism used by this AppImage launch path. The project's guide distinguishes older distributions from recent Ubuntu systems using FUSE 3. On the latter, the required FUSE 2 library can coexist with FUSE 3; replacing the current FUSE setup is not the documented repair.

For Ubuntu 24.04, the guide identifies the library package as libfuse2t64, renamed from libfuse2. Confirm the appropriate package for your actual release through its supported repositories. Ask the administrator to review the proposed package operation if the computer is managed.

Change only the confirmed dependency

Before accepting a package transaction, read its proposed installations and removals. An unexpected plan to remove desktop components is a reason to stop and recheck the instructions and release, not to approve the transaction because its command came from a forum.

After the agreed dependency correction, launch the same trusted AppImage under the ordinary user account and perform a harmless sample task. Keep the original error and the changed package information together.

If the error persists, return the exact message, release, architecture and AppImage version to the publisher. Do not mix older-distribution group or permission recipes into the current setup. Acceptance means the intended build starts and performs its sample operation; the mere presence of a package named FUSE does not establish compatibility.

Sources: AppImage documentation.