I have followed all the steps of this guy but flashing
When I open my Ubuntu console and type
fastboot flash recovery /home/username/folder/twrp-3.2.3-0-cedric.img, it says:
(bootloader) slot-count: not found (bootloader) slot-suffixes: not found (bootloader) slot-suffixes: not found (bootloader) has-slot:recovery: not found target reported max download size of 536870912 bytes sending 'recovery' (14572 KB)... OKAY [ 0.463s] writing 'recovery'... (bootloader) Image not signed or corrupt OKAY [ 0.502s] finished. total time: 0.965s
What did I do wrong? Did I use the wrong version? Looking at this similar problem did not help me.
sudo fastboot flash recovery /home/username/folder/twrp-3.2.3-0-cedric.img does not help either.