Firmware update fails after reboot

I’m trying to update my Note Pro to the latest update. I’ve downloaded the correct update file, placed it in the root directory and started the update. Everything looks good until the device powers off. When, after a few seconds it automatically powers on, I get the ‘Onyx System Recovery’ screen. At the bottom of the screen, I see these messages:

Supported API:3
Finding update package
Opening update package
E: Failed to mount /data /dev/block/platform/ff0f0000.rksdmcc/by-name/userdat (<- rest is cut off)
(Invalid argument)
E: failed to map file
Installation failed
OTA failed: Please pwoer off the device to keep it in this state and file a bug report

I selected the ‘View recovery logs’ from the top menu, but there were no files to view. Rebooting the device gets me back to the old firmware.

My current firmware version is: 2019-06-12_10-29_2.1.2_23f6dab.

… what can I do?