Auto-Align Post is an offline AAX AudioSuite plug-in.

It will work on Pro Tools 10.3.5 or greater, so you can use it with Pro Tools|HD.

Pro Tools fully supports AAX only from version 10.3.5 onward.

In order to use Auto-Align Post please make sure you're using the latest 10.3.10 release.

Also, make sure you're using MacOS X 10.7 or newer.