Can't update NextCloudPi: Sub-process /usr/bin/dpkg returned an error code (2)

I canā€™t update NextCloudPi
I canā€™t add the whole output here because Iā€™m not allowed to insert more then 4 links:
NextCloudPi v1.11.2 is outdated
update to v1.12.0 through ā€˜ncp-configā€™ or type ā€˜sudo ncp-updateā€™
Last login: Thu May 9 10:05:43 2019 from ********* (IP made irrecognizable by author)
pi@nextcloudpi:~ $ sudo ncp-update
Downloading updates
Performing updates
ā€¦
Es wurden 1.347 kB in 5 s geholt (233 kB/s).
Vormals nicht ausgewƤhltes Paket python3-cffi-backend wird gewƤhlt.
dpkg: nicht behebbarer fataler Fehler, Abbruch:
Dateilisten-Datei des Paketes Ā»libfontconfig1:armhfĀ« enthƤlt leeren Dateinamen
E: Sub-process /usr/bin/dpkg returned an error code (2)
pi@nextcloudpi:

(Update: Itā€™s the same with NextCloudPi v1.12.3)

In english via panel please have a look at the uploaded files