How To Fix RU121 - Activity & is not defined (confirmation is not possible)

RU121 - Overview

• Message type: E = Error

• Message class: RU - Messages for order completion confirmation

• Message number: 121

• Message text: Activity & is not defined (confirmation is not possible)

What causes this issue?

The work center does not have a standard value for the activity that
you have entered. Consequently, the standard value cannot be confirmed.

How to fix this error?

To confirm the activity you must first define a corresponding standard
value in the work center.

Error message extract from SAP system. Copyright SAP SE.

RU121 - Details

• The SAP error message RU121 ("Activity & is not defined (confirmation is not possible)") typically occurs in the context of production order confirmations or when trying to confirm activities in a production environment. This error indicates that the system cannot find the specified activity in the relevant configuration, which prevents the confirmation process from proceeding.
  Causes:
  
  Missing Activity Definition: The activity you are trying to confirm has not been defined in the system. This could be due to incorrect configuration or missing entries in the relevant tables.
  Incorrect Order Type: The order type you are working with may not be set up to allow for the specific activity.
  Authorization Issues: The user may not have the necessary authorizations to confirm the activity.
  Incorrect Production Version: The production version associated with the order may not include the activity you are trying to confirm.
  Master Data Issues: There may be issues with the master data related to the