The admin panel allows an administrator to add multiple specials for the same product. The administration panel handles this without issue.
The catalog side will crash with an sql error because the specials_retail_prices has a primary key on the products_id field.
Removing the primary key on the table will allow the page to load, but it breaks the specials display in the catalog, as only the last special entered for the product will be listed (multiple times, but not matching the different specials for the product).
Proposed fix is to limit the admin panel to only allow a single active special per product or change the catalog query to properly get/insert the separate values for the specials.