Flashing also rooting is always risky and you should have a backup ROM before attempting to flash or root. I think your only chance now is to find a good rom for your phone and flash it using SP Flash Tool.
Developer version update: 2014-05-30
LeWa_HUAWEI_G510-0010_JB_ROM_2014-05-30
Developer version update: 2014-05-30
LeWa_HUAWEI_G520-0000_JB_ROM_2014-05-30
Developer version update: 2014-05-30
LeWa_HUAWEI_G525-U00_JB_ROM_2014-05-30
Developer version update: 2014-05-30
LeWa_HUAWEI_Y300-0000_JB_ROM_2014-05-30
Developer version update: 2014-05-30
LeWa_SAMSUNG_I9300_JB2_ROM_2014-05-30
It looks like a problem with the backup ROM image to me. Do you have a chance to try another ROM?
Developer version update: 2014-05-30
LeWa_Jiayu_G2H_JB_ROM_2014-05-30
Developer version update: 2014-05-30
LeWa_Jiayu_G2L_JB_ROM_2014-05-30
Developer version update: 2014-05-30
LeWa_Jiayu_G2S_JB_ROM_2014-05-30
Developer version update: 2014-05-30
LeWa_Jiayu_G3_JB_ROM_2014-05-30
Developer version update: 2014-05-30
LeWa_ZTE_V889D_ROM_2014-05-30
Developer version update: 2014-05-30
LeWa_ZTE_V889S_JB_ROM_2014-05-30
Developer version update: 2014-05-30
LeWa_ZTE_V967S_JB2_ROM_2014-05-30
Developer version update: 2014-05-30
LeWa_ZTE_V970_JB_ROM_2014-05-30