Thanks Edward – I was already using version 4.5.1, but I tried downloading a ‘fresh’ copy and reinstalling, since that seems to be Zaxwerks’ solution to any problem. It had no effect, same error message, same AE freeze.
But, in goofing around with the plug-in I discovered that for some reason it was trying to open up in a older version of After Effects (that I need to keep installed for working on other people’s projects). Once I reset that Invigorator preference (in ‘Get Info’ on a Mac), everything was fine. Go figure.
Brian