Nothing happened when I clicked on the FCP alias on the desktop; the icon seems to expand momentarily, as usual, but that was it.
But I’m back in business. Thanks to your kind advice, along with an emergency phone consult with David Roth Weiss, here is what happened:
I made a copy on another computer, and then deleted (and emptied trash) the project that I thought may have caused the problem, as well as my Important Current Projects.
I tried various emergency remedies from Digital Rebellion. They didn’t have any effect but it’s nice to know they exist. (NOTE: I’m not certain that the Plug-in Manager was irrelevant to the final fix. I’ll test that when I have time, by reactivating the plug-ins that I deactivated with Plug-in Manager. But it didn’t solve the problem by itself, anyway.)
I tried my most recent Carbon Copy Clone. It didn’t work. (LESSON, from D.R.W.: always TEST your clone! LESSON from me: make at least two clones!)
I tried the drive with the older CCC – it worked. I opened my FCP project. It worked. I then Carbon-copy-cloned the clone back onto the system drive. I restarted with the system drive. I looked into restoring files from the Time Capsule but it wasn’t necessary.
All is well. Except that I will have to pull an almost-all-nighter to make my deadline. But next time, I will know exactly what to do, and will lose a lot less time as a result. And at least weekly, I’ll be making those Carbon Copy Clones!!!! and testing them.
Thanks all. I really appreciate the support, especially D.R.W.’s patience and expertise.
Bob C.