If you are using Sitecore Commerce 8.2.1 and you are defining the catalog schema you need to be aware of a couple of properties that you need to add to the catalog schema so your catalog works nicely with Sitecore Commerce Engine and the Merchandising Manager.
These properties are not in the default schema so if you are starting from scratch you need to add them yourself. If you don't, you'll get errors in the Merchandising Manager.
Catalog meta data
There are 4 properties that you need to add to the catalog meta data.
|PriceBookName||Text (max 100 characters)||When you associate a catalog with a price book, this is where the name of the price book is stored.|
|PriceBookAssociationDate||DateTime||Used to store the date the catalog was associated with the price book.|
|PromotionBookName||Text (max 100 characters)||Used to store the name of the promotion book this catalog is associated with.|
|PromotionBookAssociationDate||DateTime||Used to store the date this catalog was associated with the promotion book.|
|PriceCardName, VariationPriceCardName||Text (max 100 characters)||Used to store the name of a price card for a product or variant.|
|Tags, Variant_Tags||Text (max. 4000 characters)||Used to store the tags for a product. Tags are useful if you use tag-based price snapshots.|
Also, don't forget to add the Images properties: there are two (with the same name). Add one to the product and one to the variant.