Note: Following this tutorial is only necessary if you purchased the Mac App Store version of File Cabinet Pro. If you purchased File Cabinet Pro from AppTyrant.com, opening a folder alias will automatically work.

If you purchased File Cabinet Pro from the Mac App Store, you may have noticed that you cannot open a folder alias directly within the app. If you double click an alias folder in File Cabinet Pro, it will say “Empty Folder” in the window even if the directory is not empty. It would be reasonable to assume that this is a bug in File Cabinet Pro, but it is not.

So why does this happen?
This happens because Apple requires all apps sold on the Mac App Store to be sandboxed. The sandbox, as of macOS 10.12.1, prevents an application from accessing the contents of a folder alias; this behavior may or may not be a bug in macOS (that is for Apple to decide).

If you want to workaround this restriction, follow the steps below:
1) Launch File Cabinet Pro and bring up the app’s main window.
2) Click the gear button in the bottom left corner of the window and choose “Settings” from the pop up menu.
3) In the Settings window, under the “General” tab, click the “Grant Permission for Alias Folders” button.
4) In the system provided panel that pops up, select a directory to grant File Cabinet Pro permission to access the contents of that directory. After you select a directory, File Cabinet Pro will be able to open a folder alias if the original folder the alias points to resides within the directory you chose in the open panel. If you want to grant the app permission to open folder aliases for folders anywhere on your Mac, choose your hard disk (typically named “Macintosh HD”) in the open panel.

You only have to do the above steps once.