Message type: E = Error
Message class:  CNV_20200_CHECK - Messages for check functions (company code merge) 
Message number: 288
Message text: No house bank ID's are merged
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_20200_CHECK288 indicates that there is an issue related to the merging of house bank IDs during a data migration or conversion process, typically associated with the SAP S/4HANA migration or data transfer activities. This error suggests that the system has detected that no house bank IDs have been merged, which can lead to inconsistencies in financial data.
Cause: Missing Configuration: The house bank IDs that are supposed to be merged may not be properly configured in the system. Data Inconsistencies: There may be inconsistencies or errors in the data that prevent the merging process from completing successfully. Incorrect Mapping: The mapping of house bank IDs during the migration process may not be set up correctly. Technical Issues: There could be technical issues or bugs in the migration tool or program being used.
Solution: Check Configuration: Verify that the house bank IDs are correctly configured in the system. Ensure that the necessary settings for
 Get instant SAP help. Sign up for our Free Essentials Plan.
Get instant SAP help. Sign up for our Free Essentials Plan. 
CNV_20200_CHECK287 House bank ID &1 in company code &2
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
CNV_20200_CHECK286 Merge into (Company code &1, house bank ID &2)
What causes this issue?  Merge into (Company code &V1&, house bank ID &V2&).System Response  WarningHow to fix this error?  The busine...
CNV_20200_CHECK289 Implicit merge of house bank account ID's
Self-Explanatory Message Since SAP believes that this specific error message is 'self-explanatory,' no more information has been given.The majority of...
CNV_20200_CHECK290 Company code missing for source house bank acct ID &1
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.