probably reason of failure - not visible of false positive

Hi over there,

now it says

------------------------------------------------------------------------
C:\Users\postgres\Documents>pg_upgrade.exe --old-datadir "C:/Program
Files/PostgreSQL/12/data" --new-datadir "C:/Program
Files/PostgreSQL/13/data" --old-bindir "C:/Program
Files/PostgreSQL/12/bin" --new-bindir "C:/Program Files/PostgreSQL/13/bin"
Führe Konsistenzprüfungen durch
-------------------------------
Checking cluster versions                                   ok
Checking database user is the install user                  ok
Checking database connection settings                       ok
Checking for prepared transactions                          ok
Checking for reg* data types in user tables                 ok
Checking for contrib/isn with bigint-passing mismatch       ok
Creating dump of global objects                             ok
Creating dump of database schemas
                                                            ok
Checking for presence of required libraries                 ok
Checking database user is the install user                  ok
Checking for prepared transactions                          ok
Checking for new cluster tablespace directories             ok

Wenn pg_upgrade ab diesem Punkt fehlschlägt, dann müssen Sie den
neuen Cluster neu mit initdb initialisieren, bevor fortgesetzt
werden kann.

Führe Upgrade durch
-------------------
Analyzing all rows in the new cluster                       ok
Freezing all rows in the new cluster                        ok
Deleting files from new pg_xact                             ok
Copying old pg_xact to new server
*failure*

Prüfen Sie die letzten Zeilen von »pg_upgrade_utility.log« für den
wahrscheinlichen Grund für das Scheitern.
Fehlgeschlagen, Programm wird beendet

C:\Users\postgres\Documents>

------------------------------------------------------------------------

and the end of pg_upgrade_utility.log is

------------------------------------------------------------------------
/PostgreSQL/12/bin/pg_ctl" -w -D
"C:/Program Files/PostgreSQL/12/data" -o "" -m smart stop >>
"pg_upgrade_utility.log"2>&1
warte auf Herunterfahren des Servers.... fertig
Server angehalten
command: "C:/Program Files/PostgreSQL/13/bin/vacuumdb" --port
50432 --username postgres --all --analyze  >> "pg_upgrade_utility.log"2>&1
vacuumdb: f�hre Vacuum in Datenbank �postgres� aus
vacuumdb: f�hre Vacuum in Datenbank �template1� aus
command: "C:/Program Files/PostgreSQL/13/bin/vacuumdb" --port
50432 --username postgres --all --freeze  >> "pg_upgrade_utility.log"2>&1
vacuumdb: f�hre Vacuum in Datenbank �postgres� aus
vacuumdb: f�hre Vacuum in Datenbank �template1� aus
command: "C:/Program Files/PostgreSQL/13/bin/pg_ctl" -w -D
"C:/Program Files/PostgreSQL/13/data" -o "" -m smart stop >>
"pg_upgrade_utility.log"2>&1
warte auf Herunterfahren des Servers.... fertig
Server angehalten
command: xcopy /e /y /q /r
"C:/Program Files/PostgreSQL/12/data/pg_xact""C:/Program Files/PostgreSQL/13/data/pg_xact\" >>
"pg_upgrade_utility.log"2>&1
------------------------------------------------------------------------
again completely useless .-.-.......
best regards
Udo.