First, it seems that the path can’t be too long. Also, after discussing with a friend, that the filename should exclude (), , ;, etc. So instead always use _ and keep it simple. Seemed to work for me after those changes.
Indeed. Always use names containing only letters, numbers, underscorer (_) or hyphens (-).
Also keep this in mind for folders or hard disc name.
When in doubt of the correct path you could always use something like this :
— Pasted Max Patch, click to expand. —
Copy all of the following text. Then, in Max, select New From Clipboard.