Here my build from TL 841N v12.https://drive.google.com/drive/folders/0Bx8EHh8mvBSsejA0YzRqQnM3ZTQ
1.Flash original firmware with lede-ar71xx-generic-tl-wr841-v12-squashfs-factory-eu.bin -if router is v12 EU.
2.ssh to router
ssh 192.168.1.1
passwd - create password
retype password
cd /tmp
3.Upload lede-17.01.0-r3205-59508e3-ar71xx-generic-tl-wr841-v11-squashfs-sysupgrade.bin the /tmp directory on the router.
scp /home/user/lede-ar71xx-generic-tl-wr841-v12-squashfs-factory-eu.bin root@192.168.1.1:/tmp
4.Run sysupgrade -v -F lede-17.01.0-r3205-59508e3-ar71xx-generic-tl-wr841-v11-squashfs-sysupgrade.bin
5.Loggin to web interface
192.168.1.1
user - root
password -
Everything came up wonderfully after that.
i want do install lede for tp-link 841V v12 EU directly with factory image. but the stock firmware says
Error code: 18005
Upgrade unsuccessfully because the version of the upgraded file was incorrect. Please check the file name.