If StudioTax is unable to save your return on Mac, it is usually caused by a permission issue — macOS may be restricting StudioTax from accessing certain folders.

1. Grant StudioTax Access to the File System

macOS may be blocking StudioTax from accessing certain folders. You can grant it file system access through System Settings:

Follow Apple’s instructions to allow file system access for an app: Allow apps to access files on your Mac 

2. Try Saving to a Different Folder

Use File → Save As to save your return to a different location, such as your Desktop or a local folder. Avoid saving to iCloud Drive or other cloud-synced locations, as they can cause permission conflicts.