Solution to "Access to the path ... is denied" where path is your WBI/bin/config.txt

Service company has been successfully using WBI 7.2 for number of months.
Now when attempt to bring up the WBI login page (whether at the server, LAN computer or remote computer) get the following message:

WBI was unable to start, most likely this is due to a configuration error.
Double check your settings in the config.txt file as outlined in the documentation.
The error message is:
Access to the path ‘C:\Program Files\Ground Zero Tech-Works Inc\AyaNovaWBI\bin\config.txt’ is denied.

Confirmed all WBI installation and configuration steps.

Service company reran the WBI setup file
Restarted the application pool and website
Then retested bringing up the WBI login page, which was now successful and appears to have resolved the issue.