Can't fully install VLC on MacOS High Sierra 10.13.2

Try setting up another admin user account to see if the same problem continues. Also try the Safe Mode.

Isolating an issue by using another user account

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Safe Mode Startup – El Capitan. also Sierra

The installation of VLC 3.0 is straightforward.

1. Download from videolan.org.

   Just wait on the download screen for it to start, and do not click any green buttons.

2. Click the black download icon in the Safari toolbar, after the VLC download is complete.
   1. Double-click the VLC filename shown by the Safari download panel to start the installer.
   2. Once the installer opens, drag the orange VLC icon onto the application folder alias within the installer panel.
   3. Close the installer, and unmount it from the Desktop
3. Find the VLC icon in the /Applications folder

   RIght-click, and open it. The operating system will verify the application, and then pop a dialog about an application downloaded from the Internet. Click the Open button on this dialog.

4. Step 3 is a one-time initialization ritual for each non-Mac Store application download, including future version updates of the same application.