Item category assignment for source account &1 is deleted

What causes this issue?

During the chart of accounts conversion, the system tries to merge an
account that does not have an item category assigned with another
account that does. As a consequence, the assignment of the item category
in the Customizing settings for document splitting for the new account
&V2& would be removed when the target item category is specified by the
priority indicator (new item category = 'space').

System Response

As long as it does not have a valid item category assignment, the
account &V2& cannot take any postings if it belongs to a company code
for which document splitting is active. If you try to post an FI
document anyway, or if data from other applications gets posted
automatically in FI, you will get an error message you cannot resolve
unless you assign an item category.

How to fix this error?

Find out if the account &V2& is meant to take postings in a company code
for which document splitting is active. If this is the case, the
assignment of the priority indicator in the definition of the target
item category in the chart of accounts conversion needs to be changed
accordingly. Alternatively, you can assign a new item category manually
in the Customizing settings for document splitting.

Procedure for System Administrators

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

Error message extract from SAP system. Copyright SAP SE.