Mac Data Recovery software recovers deleted files from macOS High Sierra 10.13 startup disk. However, to restore deleted files, you need to disable System Integrity Protection (SIP) first and then run the software.

System Integrity Protection (SIP) is a security feature introduced in Mac Operating System to restrict the access of third‐party applications to system disk and partition. This feature prevents any modification in protected system files and folders on your Mac.

Follow these steps to disable System Integrity Protection (SIP):

1. Restart your Mac, press and hold 'Command + R' key until your Mac boots into Recovery Mode (macOS Utilities)

2. Under macOS Utilities screen, select 'Utilities' and from the drop‐down list, select 'Terminal'

3. In the Terminal screen, type in csrutil disable and press Return

4. Restart your Mac and new System Integrity Protection settings will take effect. Launch Mac Data Recovery