M8_UL always stuck on wcdma preferred..No singnal..Emergency calls only

Hey guyz..Me stuck in deep trouble .need help

i have M8_UL...i purchased its network unlock code...then when i insert sim..no signal..emergency calls only..but it detects sim...i officilally take ota update 4.4 to 5.0 but sme issue...what i do now..plz