This module in After Dark relies on Apple's Energy Saver software. The Energy Saver software in System 7.5.2 is incompatible with the Power Macintosh 9500 series of computers.
Ecologic module of After Dark 3.0 is compatible with the Energy Saver software in System 7.5.3 or later. You should update your system software with system software updates which can be found at Apple Computer's online software update locations.
This article can help you locate the software update mentioned here: