How To Fix MPE_RTG_UI198 - You cannot add a reference object to another reference object

SAP Error Message - Details

• Message type: E = Error

• Message class: MPE_RTG_UI - Messages for Routing Maintenance

• Message number: 198

• Message text: You cannot add a reference object to another reference object

Self-Explanatory Message

Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of messages in the SAP system have a message text, however this is frequently insufficient to comprehend or resolve the problem.

To make things easier, more detailed information is frequently added to describe the issue, how to fix it, and the necessary steps or configuration modifications.

Unfortunately, there isn't any extra information in this error notice.

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Smart SAP Assistant

• What is the cause and solution for SAP error message MPE_RTG_UI198 - You cannot add a reference object to another reference object ?

  The SAP error message MPE_RTG_UI198, which states "You cannot add a reference object to another reference object," typically occurs in the context of managing reference objects in SAP, particularly in the area of project management or resource management.
  Cause:
  This error usually arises when you attempt to create a hierarchical relationship between two reference objects. In SAP, reference objects are often used to define relationships between different entities, such as projects, tasks, or resources. However, the system does not allow one reference object to be added as a subordinate to another reference object. This restriction is in place to maintain the integrity of the data model and prevent circular references or other logical inconsistencies.
  Solution:
  To resolve this error, consider the following steps:
  
  
  Check Object Types: Ensure that you are not trying to add a reference object to another reference object. Instead, you should be adding a standard object (like a task or a project) to the reference object.
  
  
  Review Hierarchical Structure: If you need to create a hierarchy, ensure that you are using the correct object types. You may need to create a new standard object that can serve as a parent or child in the hierarchy.
  
  
  Consult Documentation: Review the SAP documentation or help resources related to the specific module you are working with (e.g., Project System, Resource Management) to understand the rules governing reference objects.
  
  
  Use Alternative Methods: If you need to establish a relationship between two reference objects, consider using alternative methods such as linking them through a different mechanism or using attributes to define their relationship without creating a direct hierarchy.
  
  
  Contact Support: If you are unable to resolve the issue, consider reaching out to your SAP support team or consulting with an SAP expert who can provide guidance based on your specific configuration and requirements.
  
  
  Related Information:
  
  SAP Notes: Check for any relevant SAP Notes that might address this specific error or provide additional context.
  Transaction Codes: Familiarize yourself with the transaction codes related to the module you are working in, as they may provide additional insights or tools for managing reference objects.
  User Forums: Engage with SAP community forums or user groups where similar issues may have been discussed, and solutions shared.
  
  By following these steps, you should be able to identify the root cause of the error and implement a suitable solution.