Message type: E = Error
Message class:  CNV_20200_CHECK - Messages for check functions (company code merge) 
Message number: 323
Message text: Company code &1 without company code for number assignment
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_CHECK323 typically indicates that there is an issue with the number assignment for a company code in the context of a data migration or conversion process. This error suggests that the system is trying to perform an operation related to a company code that does not have a valid number assignment configuration.
Cause: Missing Number Range: The company code specified in the error message does not have a defined number range for the relevant document type or object. Incorrect Configuration: The configuration for number assignment may not have been set up correctly during the migration process. Inactive Company Code: The company code might be inactive or not properly defined in the system. Data Migration Issues: If this error occurs during a data migration process, it could be due to missing or incorrect data mappings.
Solution: Check Number Range Configuration: Go to the transaction code SNRO (Number Range Objects) and check if the number range
 Get instant SAP help. Sign up for our Free Essentials Plan.
Get instant SAP help. Sign up for our Free Essentials Plan. 
CNV_20200_CHECK322 All provided source values for the business place mapping exist
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_CHECK321 Source business place (CoCd &1, business pl &2) with missing target value
What causes this issue?  Source business place (company code &V1&, business place &V2&) with missing target value.System Response  Err...
CNV_20200_CHECK324 Target company code &1 will have more than one accounting code
What causes this issue?  Target company code &V1& will have more than one accounting code. Normally accounting codes and company codes have a ...
CNV_20200_CHECK325 Conversion would lead to accounting code &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...
Click on this link to search all SAP messages.