Differences found for pattern chain &1, index &2

What causes this issue?

Differences were found in a pattern chain when the extracted DP data was
compared with the data in liveCache after the upload. These differences
relate to the list of patterns.

System Response

The difference is logged as an error.

How to fix this error?

The difference that was found indicates that a serious problem occurred
during the upgrade or the upload/download process. You must assume that
the data in the target system contains errors.
For more information, see the
<DS:REPN./SAPAPO/OM_UPGR_COMPARE_DETAIL>technical detailed log</>.

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.