There is different account assignment information in item &1

What causes this issue?

The account assignments that were planned in the service entry sheet or
the purchase order cannot be changed at the time of invoice
verification. This means that account assignment-relevant data in table
ACCOUNTINGDATA (such as G/L account, cost center) for item &SYST-MSGV1&
from table ITEMDATA cannot be different from the planned account
assignments. When comparing the data, the system has discovered a
difference.

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

System Response

How to fix this error?

Check your entries in table ACCOUNTINGDATA, and ensure that this data
matches the data from the planned account assignment.
If you want the system to automatically copy account
assignment-relevant information from the planned account assignments,
fill table ACCOUNTINGDATA according to the documentation in the BAPI
function module you are using.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.