Thanks for your help Illya.
I've managed to fix the issue using your link.
I replaced the existing Content-Security-Policy meta tag under Source WEB_RESOURCES app PageName.html, with the following:
-side note: I have changed the 'Cancel,Delete' to ['Cancel', 'Delete'] as
navigator.notification.confirm(string, function, string, string) has depreciated and replaced with navigator.notification.confirm(string, function, string, array)
However the problem is still the same.
An alternate solution would be set the empty array column to contain "[]", this avoids the error message. But i've not been able to set the column value to "[]"
Any help would be greatly appreciated