flash phone.
use/download this file at support.

R3511_G_OA[1].52.26R_PDSOOD_LPOOO4_DRM0201_JPJAVA_G_OA_L6_06_OO _14R_SE5446AXXF809F.1FF.sbf


tested on 4 L6 blank display phones due to error on unlocking.