IBM WCS - ERROR - The promotion type "" is not registered

Problem

Error upon creating a new promotion.

The promotion type "" is not registered

Cause

The error occurs when management center is not able to find the configuration for the promotion type.

Resolution

Make sure that the promotion type entry has been made within

/WebSphereCommerceServerConfig/xml/config/com.ibm.commerce.promotion/com.ibm.commerce.promotion.facade.server.config.PromotionComponentConfigurationImpl.xml

and the referenced xsl files are available.