react-notification-system | A complete and totally customizable component | Notification library

Because of the conflicts I caused by upgrading my node_modules without regard to breaking changes (dumb I know), I was only able to fix this problem by starting over. I made another create-react-app, copied my package.json (with the corrected version numbers), ran yarn install, then copied over all my program data: src, .vscode, .eslintrc, etc, etc. With a few easy fixes, this worked. No exceptions deep in the node_modules.

This is a Desktop Environment/File Manager issue. They are recognizing the file type properly but they don't execute it (as they should).

The probable cause of this issue is that the AppImage file doesn't have execution permissions (they are not preserved when the file is downloaded). The immediate solution is to ask your users to make it executable. You can achieve this by using checking the "allow execution" permission in the file properties tab of your file manager or by using the command line instruction:

chmod +x ./MyApp.AppImage.

It's also explained here https://docs.appimage.org/introduction/quickstart.html#ref-how-to-run-appimage