ubuntu 19.10 BTRFS errors

Supported
Create a snapshot of '/tmp/apt-btrfs-snapshot-mp-17n2b5n9/@' in '/tmp/apt-btrfs-snapshot-mp-17n2b5n9/@apt-snapshot-2019-10-25_07:33:56'
IO Error (open failed path:/mnt/@ errno:2 (No such file or directory)).
IO Error (open failed path:/mnt/@ errno:2 (No such file or directory)).
(Reading database ... 235820 files and directories currently installed.)
Removing megasync (4.2.5) ...
Processing triggers for mime-support (3.63ubuntu1) ...
Processing triggers for hicolor-icon-theme (0.17-2) ...
Processing triggers for gnome-menus (3.32.0-1ubuntu1) ...
Processing triggers for desktop-file-utils (0.24-1ubuntu1) ...
Invalid snapshot ''.
IO Error (open failed path:/mnt/@ errno:2 (No such file or directory)).