Set permission to allow execution, double-clicked file. It opens, arduino logo appears in center of otherwise blank screen. Logo pulses/throbs, ie. gets larger, then smaller, repeating, but nothing else happens.
Create a desktop starter or a shortcut or create an entry in a menu or in the top bar or bottom bar.
Use the whole path without a dot in front and don't use terminal mode, it is a application.
For example: /home/username/myProgs/arduino-ide_2.0.0_Linux_64bit/arduino-ide
I don't use install scripts, because I want to use different versions.
It is the same for a AppImage. Set the execute rights of the file and then use the whole path for a starter or menu entry.
I have a few AppImage files, but sometimes they use a interface that is years old and it does not work well with my split keyboard. Sometimes windows do not popup, or they can not open a file.
My split keyboard shows itself as two different keyboards. I want to press the left Shift for a capital letter on the right keyboard. That works since a few years, but not with all the AppImages.
A AppImage also needs extra time to start on a slow computer.
Thank you again Koepel. Things are now almost working. I put an Arduino logo jpg on my desktop and added properties > Open With and put /home{path]/arduino-ide, set as default, and it works, that is it opens the IDE. Major progress.
Side note: before, the appimage would not open, as described in OP. Now however it does open and seems identical to opening the application with ,/arduino-ide. Not sure what I did to make its behavior change, but it's curious.
I'm now researching why it shows no ports and won't upload a file to my board. Separate thread.
Many thanks again for your time and expertise.
Jay