It was pretty radical surgery, but this worked:
I renamed the hard drive from "Don's Laptop" to "djlaptop", eliminating the apostrophe as well as the caps and space, just in case.
Removed entire Creative Suite.
Ran Adobe CC Cleaner tool.
Removed all Adobe preferences
Reinstalled Dreamweaver and CC Desktop Application Manager
Reinstalled Extention Manager
Reinstalled WA Databridge
Opened new PHP document
Completed Databridge download upon document open
Opened PHP doc and used Webassist pull-down.
It's strange how the WA plugin has previously worked fine on the same hard drive, then just stopped working without any obvious reason.
Now it's time to download the rest of the CC. Lots of work, but worth it.
Thank you for your help, Jason. I appreciated your call.