There appears to be an incompatibility with the Soft SampleCell extension and some other extensions, such as extensions for some USB and Firewire devices. A couple of known extensions that can cause an extension conflict:
Radialogic Firewire drivers, specifically the "Radialogic ATA/SCSI Driver" extension.
Newer Technology USB uDrive extension(s). Disabling the uDrive extension(s) in Extensions Manager resolves the issue.
If you have an extension installed that conflicts with the Soft SampleCell? INIT, when you start up your CPU the Soft SampleCell? extension will show up with a red cross and will not load, which means you can't use Soft SampleCell
There are two workarounds for this:
Disable the conflicting extension in the extension manager and reboot your computer.
Or, make sure that the Soft SampleCell? extension loads first by adding a space at the beginning of the file name in your System Folder > Extensions folder. "Soft SampleCell?" should look like " Soft SampleCell?". Reboot your computer and the Soft SampleCell extension should load.