So to resume:
The problem
After I flash(I checked the option to keep config berore I flash it...) the my TP-Link TL-WA901NND v4 (from 18.06.5 to 18.06.8) my Luci enviroment broke.
/usr/lib/lua/luci/dispatcher.lua:234: /etc/config/luci seems to be corrupt, unable to find section 'main'
stack traceback:
[C]: in function 'assert'
/usr/lib/lua/luci/dispatcher.lua:234: in function 'dispatch'
/usr/lib/lua/luci/dispatcher.lua:127: in function </usr/lib/lua/luci/dispatcher.lua:126>
The Solution
So the only solution founded was connect through Putty(SSH) with user and password.
And follow type this commands:
root@LEDE:~# mount_root
root@LEDE:~# firstboot
This will erase all settings and remove any installed packages. Are you sure? [N/y]
y
/dev/mtdblock3 is mounted as /overlay, only erasing files
root@LEDE:~# reboot -f
After this the Luci enviroment will work but you will need setup the router again.
Thanks everyone for the help!