With the PHP version set to 7.1, Dreamweaver does not appear to recognize all of 7.1 feathers.
for example, declaring visibility in classes for const the line --- protected const MY_CONST = 123; --- shows as an error. Also, it does not seem to recognize the intdiv (Integer division) command.
Found the problem. The version has to be set with the site in addition to Dreamweaver's preference.