On pages with multiple products showing, the error, “The _validateExp0 validator has already been loaded” is appearing in Firefox version 54. This is a result of Firefox updating it's javascript engine.
The quick fix is to remove the javascript on CFWebstore that is triggering the error.
Go to products/listing/put_orderbox.cfm ~ line 280 and comment out:
All this does is enforce multiples if you've entered them in the admin for the product. If you don't use that feature then this will fix the problem.