Windows 3.1 and QuickTime 2 are limited and don't work with some things in my latest QTVRs. Solution: upgrade to QuickTime 3 or higher.
Memory needs are up for the new features and the rich 3D space. Solution: Give the browser more disk space and more cache space.
Plug-in must be installed correctly because the browser needs the plug-in to do the display. Solution: For each browser you use, be sure the QTVR plug-in is in the plugins directory in the same directory as the browser. You only need one plug-in file. The rest can be short-cut or aliases to the original. Be sure there is one original.
MIME types need to be enabled in the plug-in. Solution: In a QuickTime window popup the settings menu and select
Plug-in settings and MIME settings. Enable the MIME types you want. See
also the information given for Wrinkle 2000, which is called Windows
Advisory, but the information is applicable to any platform.