Entries were created for &1 documents in the index

What causes this issue?

The report has created the document index (info structure S111)
sucessfully and finished processing the document range.

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?

You can display info structure S111 using transaction SE16 (Data
Browser).

Error message extract from SAP system. Copyright SAP SE.