Adb Sideload Not Working

[BlackMi]

I wanted to update my rom to xiaomi.eu rom

After unlocking the bootloader and flashing TWRP, i now cannot install the rom, because the zip isn't on the SD anymore!

I do not succeed in installing it via fastboot, because i cannot find any img of the rom.

So i tried installing it via ADB sideload, but everytime i start the adb sideload feature TWRP writes "Starting ADB sideload feature..." for about 5 minutes then writes failed on top.

*Edit*
Unfortunately booting into old rom only leads to bootanimation

 

[Papka__]

Install TWRP I posted here. It's with MTP, so you will be able to upoload ROM in TWRP.
From the other side, I suggest you to go full chain and flash starting from Native android. Then boot into Native android, connect to PC and upload xiaomi.eu ROM. Install TWRP and not wiping internal storage, boot into TWRP and install ROM saved on internal storage.

 

[BlackMi]

Thank you for your fast answer @Papka__

Somehow i managed to get the zip file on the tablet while beeing in TWRP
Installed it, but the device doesn't boot.

Now i tried to install en.miui rom via MiFlash, which worked, bootloader is still unlocker, so i should be able to flash TWRP and install ROM shouldn't I?

 

[BlackMi]

So, i did it,
it worked,
but now there is another problem:
The device is locked by mi account and i am not able to unlock it, because there is no keyboard

 

[Papka__]

I really recommend you to completely re-flash from fastboot using tutorial I re-posted here. You will avoid a lot of problems including this.
Flash Native android, then TWRP 3.0.0.0, then dev from here and finally SuperSu.