Dorico 4 install & activation went fine…Almost – Dorico

Upgraded to Dorico 4 from Dorico 3.5.

Install and activation went fine.

when I open Dorico 4 I I get to the Splash Screen:

“Audio Engine: Waiting for connection”

Then up pops a dreaded Red Circle with the White X in the center saying:

“Unknown ApplicationAn unknown interapplication communication error occured. In case the problem persists, please close all applications and restart your computer.”

I have rebooted the computer 4 times and everytime I open Dorico 4 I repeat the process.

Anybody else have this occur ?