I am very familiar with the tricks software companies play when you report a bug. They always say, "When we try it, it always works!"
Since I did not know what the permissions should be, I changed all permissions to rwx; that should not hurt.
Presets directory permissions are
drwxr-xr-x@ 39 user_name staff 1248 Jan 7 14:57 Presets/
slightly more than yours dwr-------@, but that should not matter.
The Presets directory is in the correct location
/Users/user_name/Documents/VSL/Vienna Synchron Player/Presets
Everything at this stage is fine.
There is no difference between /Users/user_name/Documents/ and /Users/user_name/Documents with / removed—the same rainbow spinning wheel.
This cannot be entered in the file name /Users/user_name/Documents/VSL/Vienna Synchron Player/Presets/#01 01 1st Violins - VelXF sus.vsynpreset to load a single Preset file,
or /Users/user_name/Documents/VSL/Vienna Synchron Player/Presets/
or /Users/user_name/Documents/VSL/Vienna Synchron Player/Presets
with the "/" after Prests cannot be entered. The error is Please enter a valid folder name:
We are back to where we started from.
I will wait a little while until you fix the bug/bugs.