Symptom
An application or installer opens, but doesn't use Classic. The application's plug-ins don't work without Classic.
Products affected
Solution
Some applications are made to work with both Mac OS 9 and Mac OS X. If you double-click one of these applications while using Mac OS X, it will open as a Mac OS X application without starting Classic.
However, some Classic applications have plug-ins and other resources that are only available if you use them with Classic. Some installer applications, for example some third-party printer driver installers, will automatically detect whether they are opened in Mac OS 9 or Mac OS X and only install the components appropriate to that operating system.
To avoid this issue, you can have the application or installer always open using Classic.
Select the application or installer and choose Show Info (Mac OS X 10.1 or earlier) or Get Info (Mac OS X 10.2 or later) from the File menu, then select the checkbox to have the application open using Classic.
Note: If the installer application is located on a read-only volume, such as an installation CD, it, and any files it needs for installation, must be copied to a read-write volume first. If you cannot install in this way, contact the manufacturer of the software for compatibility information and further assistance.