Here's the key line from the log:
Attempting to open http://127.0.0.1:43690\LuluCam\ with Chrome: C:\Program Files (x86)\Google\Chrome\Application\chrome.exe
This path does exist and the chrome.exe file does launch Chrome.
SOLVEDTried suspending Firewall and AV but it made no difference.It seems that it is necessary to run AppStudio.exe as an administrator. By setting this in AppStudio.exe properties Chrome now launches successfully. Turn it off and we get the error message again. On: no problem.
Thanks for the good news!