How To Fix TR301 - Reservation entry &1 &2 &3 already exists; no inserts possible

SAP Error Message - Details

• Message type: E = Error

• Message class: TR - Change and Transport System

• Message number: 301

• Message text: Reservation entry &1 &2 &3 already exists; no inserts possible

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.

What else can you do?

First, use our AnswerBot below to get a possible cause and solution (requires a premium subscription).

Also, review the in-depth Common Questions & Answers listed below; you could discover a solution there or be able to connect with others who have faced similar challenges.

You can also try searching the SAP support portal (support.sap.com) but you need a special user ID to access it. It is possible that an SAP support note exists that provides additional details about the mistake or even steps for fixing it.

Smart SAP Assistant

• What is the cause and solution for SAP error message TR301 - Reservation entry &1 &2 &3 already exists; no inserts possible ?

  The SAP error message TR301 indicates that there is an attempt to create a reservation entry that already exists in the system. This typically occurs when you try to insert a new reservation for a material that has already been reserved with the same parameters (such as material number, plant, storage location, etc.).
  Cause:
  
  Duplicate Reservation: The most common cause is that a reservation with the same details (material, quantity, plant, etc.) already exists in the system.
  Concurrency Issues: If multiple users or processes are trying to create reservations simultaneously, it may lead to conflicts.
  Data Integrity Issues: There may be issues with the data being processed, such as incorrect or incomplete information.
  
  Solution:
  
  Check Existing Reservations: Before creating a new reservation, check if a reservation with the same details already exists. You can do this by using transaction codes like MB21 (Create Reservation) or MB22 (Change Reservation) to view existing reservations.
  Modify Existing Reservation: If a reservation already exists and you need to change it, consider modifying the existing reservation instead of creating a new one.
  Use Unique Parameters: Ensure that the parameters you are using to create the reservation are unique. This may involve changing the quantity, date, or other relevant fields.
  Error Handling in Code: If this error occurs in a custom program or interface, implement error handling to check for existing reservations before attempting to create a new one.
  Consult Documentation: Review SAP documentation or consult with your SAP support team for specific guidelines related to your version and configuration.
  
  Related Information:
  
  Transaction Codes: Familiarize yourself with relevant transaction codes such as MB21 (Create Reservation), MB22 (Change Reservation), and MB23 (Display Reservation).
  SAP Notes: Check SAP Notes for any known issues or patches related to this error message.
  User Authorization: Ensure that the user has the necessary authorizations to create or modify reservations.
  System Logs: Review system logs for additional context or related errors that may provide more insight into the issue.
  
  By following these steps, you should be able to resolve the TR301 error and successfully manage reservations in SAP.