@Lakotaubp Sorry for that. I deleted the other post.
At the moment i did a successfull unlock. From Linux it works. :-))))))))

Re: Sony Xperia X (suzu/F5121)

I bought a Sony Xperia X to use with UBports. I upgraded the device to the latest Android 8 version but i am still not able to unlock the bootloader.

Bootloader allowed says Yes.
fastboot devices says that it recognise the device
fastboot oem unlock 0x..... says: FAILED (remote: 'unknown command')
fastboot getvar all shows up: bootloader secure: yes

I am stuck for know. I can't use the EMMA tool also because EMMA says that the device is locked.

Can someone please give me a hint?

Thanks in advance.