"Continue" button greyed out when installing .pkg Update: There is no solution.  After I got the .qtz file into /Library/Compositions, it didn't work, and then I found out that third-party visualizers have been disabled as of iTunes 12.6.  It may still work on previous iTunes versions, but I do not know.



On 10.12.6, I am trying to install an iTunes visualizer, but there's no way to progress past this screen.



It is supposed to be installed to /Library/Compositions, so I tried

sudo installer -pkg ~/Downloads/wowlab_oneday_1.0.1/wowlab_oneday_1.0.1.pkg -target /Library/Compositions


The result was:

installer: Error trying to locate volume at /Library/Compositions


The same error occurred regardless of the destination specified.

These are the files Installer wants to install:



When I expand wowlab_oneday_1.0.1.pkg with Unarchiver, it contains a Resources folder, Distribution file, and wowlaboneday.pkg.  This second .pkg can't be extracted with Unarchiver.  When I click Show Package Contents, it contains Bom, PackageInfo, and Payload.

How can I get the .qtz file out and into /Library/Compositions, presuming that's what needs to be done?
From man installer:

SYNOPSIS
 installer ... -package &lt;pathToPackage&gt; -target device

[...]

A device parameter for the target is any one of the following:

 1) Any of the values returned by -dominfo
 2) The device node entry.  Any entry of the form of /dev/disk*.  ex: /dev/disk2
 3) The disk identifier.  Any entry of the form of disk*.  ex: disk1s9
 4) The volume mount point.  Any entry of the form of /Volumes/Mountpoint.  ex: /Volumes/Untitled
 5) The volume UUID.  ex: 376C4046-083E-334F-AF08-62FAFBC4E352


So try sudo installer ... -target / instead.

If this fails there is also the option of using Pacifist to extract the content of the package and install it manually (or do whatever you like to do with it).