Apache httpd does not start with error "DocumentRoot must be a directory"

Issue

• Apache webserver fails to start on booting, as well as with service httpd restart, with the following error:

# service httpd start 
Starting httpd: Warning: DocumentRoot [/xxx/yyy] does not exist 
Syntax error on line 287 of /etc/httpd/conf/httpd.conf: 
DocumentRoot must be a directory 
                                                               [FAILED]