This is typically a problem in MacOS, where FileZilla Pro has been purchased from the MacApp Store and you didn’t grant access to your local directories yet.
As a standard security measure, Apple’s Sandbox denies local file system access to apps from the App Store.
To grant access to local files:
- In FileZilla, select Edit > Directory access permissions.
- Add the directories that you want FileZilla Pro to access.
- Click on OK.