I just installed Ventura on a Mac Mini. I have a soft link to a file with a
file extension defined in a 3rd party application. In Finder, when the primary copy of the file is "clicked on", the file is loaded into the application with
no problem. However, the soft linked file is "clicked on", Finder cannot find
which application is associated with the file. Both the file and and soft link used the same extension.
Mac mini, macOS 13.5
It looks like what you have made there are actually "symbolic links". I can tell that because of the small size. Symbolic links are a unix file system object and some 3rd party apps may not work properly with them. How a Mac decides what it can and can't open from the Finder or an app is extremely complicated. It is far more than just chasing the extension. There is lots of internal metadata for the associated app that has to be just perfect.
Plus, to make matters even more complicated, you said you had just installed Ventura. Another possibility is that the Spotlight index hasn't completely updated. That can cause all kinds of problems.
Here are a few things you can try:
1) A different app. You are running some kind of "Open" something. That sounds like some poorly maintained and poorly ported open source app. I have no problems when I reproduce what you are trying with Excel, for example.
2) A Finder alias. Did I mention how confusing this is? The Finder is calling all of those symbolic links "Aliases", but they aren't. A true Finder alias would be anywhere from 900 bytes to 9,000,000 bytes in size. (Even if the original is only 9 bytes). You can hold down the option and command keys while dragging a file to create a Finder alias. Apps that don't work well with symbolic links might understand a Finder alias, or vice-versa.
3) Just copy the file. You are trying too hard to manually optimize. The operating system already creates zero-byte links when you make a copy of a file. So you are actually using more storage by trying to create aliases. If you modify the copy, then it won't change the original, however, if that is what you are trying to do.
And finally, when apps save files, they are very likely to do some very funky things that not at all compatible with symbolic links, or aliases for that matter. They will typically create a new directory, write the entire new file in that new directory, and swap it out with the old one. Rest assured that any manual optimizations you are trying are a total waste of your time.
Soft linked file has problem opening 3rd party app in Finder
