Downloaded your modular navigation bar (bootstrap) and it works like a charm, as shown below:
However, when I try the categories module, it does not work at all. I just end up getting a blank page with "Site Settings" text at the top left hand side of the browser screen as shown in the image below:
I''m at the moment running responsive oscommerce with php 7.1 on mysql 5.7. Have you encountered this problem before?