Message type: E = Error
Message class:  CNV_OM - Messages for Objectbased Migration 
Message number: 037
Message text: Deactivating preselection task &1
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 CNV_OM037, which indicates "Deactivating preselection task &1," typically occurs in the context of data migration or conversion processes, particularly when using the SAP S/4HANA Migration Cockpit or similar tools. This error suggests that there is an issue with a preselection task that is preventing it from being executed or completed.
Cause: Inconsistent Data: The preselection task may be encountering data that does not meet the required criteria or is inconsistent, leading to its deactivation.
Configuration Issues: There may be configuration settings that are not properly set up, causing the task to fail. Missing Authorizations: The user executing the task may lack the necessary authorizations to perform the operation. Technical Errors: There could be underlying technical issues, such as system performance problems or bugs in the migration tool.
Solution: Check Data Consistency: Review the data that is being processed by the preselection task. Ensure that it meets all necessary criteria and is consistent. Review Configuration:
 Get instant SAP help. Sign up for our Free Essentials Plan.
Get instant SAP help. Sign up for our Free Essentials Plan. 
CNV_OM036 Deactivating preselection tasks
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
CNV_OM035 Select at least one valid line item. Generation state must be non-initial
What causes this issue?  To execute the activity for an MWB object, the generation state must not be initial. However, the selected line items have ge...
CNV_OM038 No tasks to be deactivated
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
CNV_OM039 No tasks for current ES &1 / Run-ID &2
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.