To re-open this thread...
-- url of the page with the problem -- : (now fixed)
-- HikaShop version -- : HikaShop Business 2.6.1
-- Joomla version -- : 3.4.8
-- PHP version -- : 5.4.45
-- Error-message(debug-mod must be tuned on) -- : none
I had the same problem. Namely an associated module showing at the bottom of my page. Except instead of a category menu, this one is a product menu.
I made it a long time ago, and I think it initially started out as a category menu.
The modules could not be deleted, or actually even found at all. The ID the module purported to have was nowhere to be found, so I couldn't access it in modules, menus or in Hikashop. There were a ton of "Associated modules" in the module manager, but I deleted them all and the phantom modules still persisted.
However, I was able to solve the problem simply by going into the Product options of the menu item, changing something, then saving again. After this, the module simply disappeared.
I have to stress, though. I had to change something in the Product options. You can't just open it and save it again. In my case, I just switched the Random Items setting to "inherit", saved, then checked the page to make sure it was gone. When it was, I switch the Random Items back to "no".
For whatever reason, I had to do this with several menu items recently. It seems like you need to force the system to realize those modules don't exist somehow. Although I did empty the site cache and that didn't do it.
Anyway, I thought I'd post it here in case it could help someone else.