Message type: E = Error
Message class:  U9 - Message Class for Output in Application Log 
Message number: 556
Message text: Routing does not exist in table PLAN
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The SAP error message U9556, which states "Routing does not exist in table PLAN," typically occurs when the system is unable to find a routing for a specific material or production order in the routing table (PLAN). This can happen for several reasons, and here are some common causes, solutions, and related information: Causes: Missing Routing: The routing for the material or production order has not been created or has been deleted. Incorrect Material or Plant: The material or plant specified in the order does not have an associated routing. Routing Not Active: The routing exists but is not active or valid for the specified period. Incorrect Configuration: There may be issues with the configuration settings in the production planning module. Data Inconsistency: There may be inconsistencies in the master data or configuration that prevent the routing from being found. Solutions: Check Routing Existence: Use transaction code CA03 (Display Routing) to check if the routing exists for the material
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