I've now installed the plugin version of Mercalli for use with my iMac, this has also not started well. I downloaded the package without any problems and then also installed it without any problems, so far so good.
The plugin appears fine in the video filters list and I went into this again with my hopes raised, to no avail. I loaded a couple of clips (MOV files) into the timeline and tried to apply the Mercalli filter to the clips, I was greeted with the screen below:
Can it get any more depressing?
Waiting to hear from proDAD.