Errors occurred during post-handling & for & &

What causes this issue?

During the upgrade, import post-processing &V1& was performed for
object &V2& &V3&. Errors were reported.

System Response

The upgrade is interrupted.

How to fix this error?

You will find the error messages for post-processing &V1& directly
before this message. First read these error messages and the respective
long texts. You will find further information there on correcting the
errors.
If this information is not sufficient, look for error notes in the
SAPNet - R/3 Front End. Keywords you can use for the search are
the name of post-processing &V1& or
the message numbers of the preceding error messages. The message number
appears in the header of the long text display.
If you enter a problem message for the error, enter the following
information:
the name of post-processing &V1&
the message numbers of the preceding error messages
the components in which the error occurred

Error message extract from SAP system. Copyright SAP SE.