There is a known issue affecting the Mac and PC Pro Tools AAX versions of Auto-Tune Pro and older versions of Auto-Tune 8.0.x (Auto-Tune+Time).
Specifically, having both Auto-Tune Pro and Auto-Tune+Time (8.0) installed and loaded in a Pro Tools session at the same time will cause erratic graphic display behavior and crashing. To avoid this issue, do not use Auto-Tune+Time (8.0) and Auto-Tune Pro in a Pro Tools session at the same time.
If possible, uninstall Auto-Tune+Time (8.0) to avoid the risk of accidentally loading it in a session that also has loaded instances of Auto-Tune Pro. The simplest way to uninstall Auto-Tune+Time (8.0) is to manually remove the AAX plugin file from your system's AAX plugin folder in the following locations on Mac and PC, respectively:
Macintosh HD/Library/Application Support/Avid/Audio/Plug-Ins/Antares Audio TechnologiesC:\Program Files\Common Files\AVID\Audio\Plug-Ins