Note the location of the SweetHome3D start script. This is the script you edited before.

Right click on a .sh3d file
Click "Open With Other Application"
Navigate to the SweetHome3D script and select to open with that script.
Don't forget to mark "Remember this applicatpon for sh3d documents".

From now on double clicking on a sh3d file should start SweetHome3D with the clicked file.

(This is on Debian but it's probably the same on Elementary.)

Thank you @Keet for your suggestion.

I tried it, but unfortunately i haven't seen any option like "open with that script" or "navigate to folder".

In the Files program, i make a right-click on my .sh3d file, then "open with > other application". There is no further option like "open with -> navigate to folder" or "navigate to script".


Would you know how to solve this?

I tried also Option 3. Set default apps via MIME type (Universal) (Link https://fostips.com/default-apps-opening-files-ubuntu)

with these commands

Try 1 Try 2 But it didn't helped. i was still unable to open my sh3d file in sweethome3D while double-clicking on the file.