Systemback - There has been critical changes in the file system during this operation (lxcfs)

Hey,
I have an Ubuntu-Server for using Nextcloud and want to have restore points in case something goes wrong.
I tried using Systemback, but gave me an error message.

Here is the output of /tmp/systemback-cli_stderr:

Version: 1.8.402_05.16.2016_Qt5.9.5(5.5.1)_GCC5.3.1_amd64
Compilation date and time: May 16 2016 11:15:56
Installed files: /etc/xdg/autostart/sbschedule-kde.desktop
                 /etc/xdg/autostart/sbschedule.desktop
                 /usr/bin/systemback
                 /usr/bin/systemback-cli
                 /usr/bin/systemback-sustart
                 /usr/lib/systemback/libsystemback.so
                 /usr/lib/systemback/libsystemback.so.1
                 /usr/lib/systemback/libsystemback.so.1.0
                 /usr/lib/systemback/libsystemback.so.1.0.0
                 /usr/lib/systemback/sbscheduler
                 /usr/lib/systemback/sbsustart
                 /usr/lib/systemback/sbsysupgrade
                 /usr/share/applications/systemback-kde.desktop
                 /usr/share/applications/systemback.desktop
                 /usr/share/systemback/efi-amd64.bootfiles
                 /usr/share/systemback/lang/systemback_ar_EG.qm
                 /usr/share/systemback/lang/systemback_ca_ES.qm
                 /usr/share/systemback/lang/systemback_cs.qm
                 /usr/share/systemback/lang/systemback_da_DK.qm
                 /usr/share/systemback/lang/systemback_de.qm
                 /usr/share/systemback/lang/systemback_en_GB.qm
                 /usr/share/systemback/lang/systemback_es.qm
                 /usr/share/systemback/lang/systemback_fi.qm
                 /usr/share/systemback/lang/systemback_fr.qm
                 /usr/share/systemback/lang/systemback_gl_ES.qm
                 /usr/share/systemback/lang/systemback_hu.qm
                 /usr/share/systemback/lang/systemback_id.qm
                 /usr/share/systemback/lang/systemback_pt_BR.qm
                 /usr/share/systemback/lang/systemback_ro.qm
                 /usr/share/systemback/lang/systemback_ru.qm
                 /usr/share/systemback/lang/systemback_tr.qm
                 /usr/share/systemback/lang/systemback_uk.qm
                 /usr/share/systemback/lang/systemback_zh_CN.qm
Operating system: Ubuntu 18.04.3 LTS
Mounted filesystems: /dev/sdb2 / ext4 rw,relatime,data=ordered 0 0
                     /dev/loop0 /snap/core/7917 squashfs ro,nodev,relatime 0 0
                     /dev/loop1 /snap/nextcloud/16232 squashfs ro,nodev,relati
                     me 0 0
                     /dev/loop2 /snap/stress-ng/847 squashfs ro,nodev,relatime
                      0 0
                     /dev/loop4 /snap/nextcloud/16402 squashfs ro,nodev,relati
                     me 0 0
                     /dev/loop3 /snap/core/7713 squashfs ro,nodev,relatime 0 0
                     /dev/loop5 /snap/stress-ng/792 squashfs ro,nodev,relatime
                      0 0
                     /dev/sdb1 /boot/efi vfat rw,relatime,fmask=0022,dmask=002
                     2,codepage=437,iocharset=iso8859-1,shortname=mixed,errors
                     =remount-ro 0 0
                     /dev/sda1 /mnt/cloudStorage ext4 rw,relatime,stripe=8191,
                     data=ordered 0 0
System language: C
Translation: -

An error occurred while cloning the following file:

 /var/lib/lxcfs/cgroup/devices/devices.deny

Target file:

/home/Systemback/.S00_2019-10-12,15.13.40/var/lib/lxcfs/cgroup/devices/devices.deny

/var/lib/lxcfs/cgroup/devices/devices.deny
 f -w------- 1 0 0 50 0B
/var/lib/lxcfs/cgroup/devices
 d rwxr-xr-x - 0 0 50 -
/var/lib/lxcfs/cgroup
 d rwxr-xr-x - 0 0 50 -
/var/lib/lxcfs
 d rwxr-xr-x - 0 0 50 -
/var/lib
 d rwxr-xr-x - 0 0 2066 -
/var
 d rwxr-xr-x - 0 0 2066 -

/home/Systemback/.S00_2019-10-12,15.13.40/var/lib/lxcfs/cgroup/devices/devices.deny
 -
/home/Systemback/.S00_2019-10-12,15.13.40/var/lib/lxcfs/cgroup/devices
 d rwxr-xr-x - 0 0 2066 -
/home/Systemback/.S00_2019-10-12,15.13.40/var/lib/lxcfs/cgroup
 d rwxr-xr-x - 0 0 2066 -
/home/Systemback/.S00_2019-10-12,15.13.40/var/lib/lxcfs
 d rwxr-xr-x - 0 0 2066 -
/home/Systemback/.S00_2019-10-12,15.13.40/var/lib
 d rwxr-xr-x - 0 0 2066 -
/home/Systemback/.S00_2019-10-12,15.13.40/var
 d rwxr-xr-x - 0 0 2066 -
/home/Systemback/.S00_2019-10-12,15.13.40
 d rwxr-xr-x - 0 0 2066 -
/home/Systemback
 d rwxr-xr-x - 0 0 2066 -
/home
 d rwxr-xr-x - 0 0 2066 -

Errno: 13

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I read on another thread that a similar issue has been fixed.
Sadly it doesn't work on my server.

Thank you for your work.