We have recently updated a Magento site to version 1.12. Now the site wont retrieve up-sell products to product details page anymore. No custom code changes committed and no target rules specified. Still the up-sell product relations are visible in back end and in the catalog_product_link table as well. But I always get an empty result set to template\targetrule\catalog\product\list\upsell.phtml.
Anyone came across a problem like this? Are there some other conditions that needs be satisfied in order to show up-sell products? May by my database update scripts haven't run correctly. If so what are the tables/modules I should have a look at?
Did you run reindexing.
For product collections flat tables are used.This needs reindexing.
Also make sure you clear your cache after reiundexing.