Do this only if you are familiar with installing and uninstalling Macintosh hardware. If you are not, and you believe the problem is hardware related, consider taking your Macintosh to a qualified service provider for help. Another possible cause is one or more SCSI devices. Try troubleshooting the SCSI chain to determine if this is the case. If, after performing these solutions, the error recurs, your hard disk may have problems such as bad sectors or a corrupted directory tree.
Possible Solutions Try adjusting compatibility settings.
Enabling this option will likely eliminate incompatibilities causing the Type 15 error, but will slow performance. If you are using a 68K Macintosh, another possible, but less likely cause may be an incompatibility with 32-bit addressing. If you are using non-native software on a Power Macintosh, disable Modern Memory Manager in the Memory control panel. Modern Memory Manager is used by native software and older, non-native software is unable to take advantage of it. QuickDraw GX is included with System 7.5 and later and is intended to improve printing to non-PostScript printers.