Message type: E = Error
Message class:  /SEHS/DG_DG -  
Message number: 301
Message text: Engineering change management: Change number &1 is locked
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.
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.
The SAP error message /SEHS/DG_DG301 indicates that a specific engineering change number (ECN) is locked, which prevents any modifications or actions related to that change number. This locking mechanism is typically in place to ensure data integrity and prevent concurrent modifications that could lead to inconsistencies.
Cause: Active Lock: The change number is currently being edited or processed by another user or session. Incomplete Transactions: A previous transaction involving the change number may not have been completed, leaving it in a locked state. System Configuration: Certain configurations or settings in the Engineering Change Management (ECM) module may enforce locks under specific conditions.
Solution: Check Lock Entries: Use transaction code SM12 to check for lock entries related to the change number. You can identify the user or session that is holding the lock. Release Locks: If you have the necessary authorizations, you can manually delete the lock entries in SM12. However, be cautious with this approach, as it
 Get instant SAP help. Sign up for our Free Essentials Plan.
Get instant SAP help. Sign up for our Free Essentials Plan. 
/SEHS/DG_DG300 Engineering change management: Change number &1 not found
What causes this issue?  The change number &V1& you entered does not exist.System Response  The system rejects your entry.How to fix this erro...
/SEHS/DG_DG299 ------------- Engineering Change Management up to no. 350 ---------------
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
/SEHS/DG_DG302 Object type for change master record does not support changes
What causes this issue?  In the change master record, the object type is configured so that objects of this type cannot be changed. Either these chang...
/SEHS/DG_DG303 *Object type does not support changes & object does not exist.
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
Click on this link to search all SAP messages.