Due to the macOS sandbox disk access is is limited to certain folders that are specified in an App's .entitlements files. For the standalone app, it's possible to specify these ourselves (there is a quite limited selection) see #250, but in a DAW they will be specified by the host app. It's common practice to store presets these days in the users "Music" folder with a subfolder for the product name.

I suggest using the folders ~/Music/NeuralAmpModeler/Models and ~/Music/NeuralAmpModeler/Impulses or similar.

Without this, the popupmenu and navigation controls that I added in #242 will fail if people try to load files outside the macOS sandbox, basically the menu will not be populated with adjacent files to the selected one, because all the posix file system APIs will fail outside the sandbox.