For some reason, the jojo_robots.php setting of header content-type to txt was not correctly setting that header.  - the jojo.php setting of header as html was taking precedence. 
For some reason, the jojo_robots.php setting of header content-type to txt was not correctly setting that header. 
- the jojo.php setting of header as html was taking precedence. 

So in jojo.php checked for presence of .txt in url and so set not just robots.txt to header content-type txt but all .txt files

JojoCMS/Jojo-CMS,JojoCMS/Jojo-CMS,JojoCMS/Jojo-CMS