Can't Root xperia S after installing new Lollipop mod

Hello, i have a sony xperia S, i rooted it before using the king root (with pc) and then installed a lollipop mod, after installing the mod (which was a beta version) i couldn't format the phone ( and some other minor issues ) and the root was gone , so when i tried to root it again using king root it didn't work, i tried many other methods too (with and without pc) but all failed to root .. they recognize the phone as xperia S when im about to root and tell me that the strategy available to root but all fail at the end.. is there a way to root my phone with this lollipop mod ?
Thanks