Users can't edit any any of there products. It links to the Oops! That page can’t be found.
An item can be edited before while it is pending. An Auction can not be edited under products but can in the Auction section.
Did you set your pemalinks as Post name and Product?. If yes, then i have to check your site. Please provide your login details by using this form- http://wedevs.com/provide-login-details/. I will have a look what is going wrong.