Business partner &1 is not stored in database yet. Please refresh.

What causes this issue?

If you just created a business partner and you are sure that the
business partner exists, this error may be caused because the new
business partner data have not been stored in the database yet. By the
time this message is displayed, it is likely that the business partner
data have been stored in the database. Please manually enter the busi
ness partner number in the appropriate field and click the
"Refresh"-button.

System Response

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

How to fix this error?

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.