Chem3D crashes when I launch.
Try disabling the Navigation Manager extension using your Extensions Manager control panel.
More background on the Navigation Manager extension can be found in the Chem3D ReadMe on the cd-rom:
The Navigation Manager is an Apple technology that supplies enhanced dialog boxes for opening and saving files. It is available as a system extension for MacOS 7.6-8.1 and is built into the system on System 8.5. Among the features of the technology are:
1. The ability to open several files simultaneously
2. The ability to eject removable media from within the dialog box
3. Enables the user to switch to another application when the dialog box is visible
4. A built-in interface for previewing text documents
5. A list of recently opened items by file format is maintained
6. A list of user-specified favorites is maintained
7. Enhanced navigation in the file hierarchy by being able to use expansion triangles in the dialog box
8. A resizable dialog box so users can see more or fewer files
CambridgeSoft installers do not install this extension under system 7.6 or below because under these systems the extension has bugs that cause opening files to generally fail. We also do not install under system 8.5 because the extension is built-in. We do install this extension under systems 8.0-8.1. Under Mac OS 8.0 and 8.1, there are problems opening files from Windows disks, but not Mac disks. If you remove the extension, this problem will not occur and you will see the old dialog boxes for opening and saving files.