Default hi need help E: failed to mount /efs (invalid argument)

hi
i need help about E: failed to mount /efs (invalid argument) problem
i was trying flash something to my galaxy s2 after booting from recovery i stuck in bootloop.i think i do some thing wrong i flash stock rom but again stuck in bootloop.i go back to recovery then i find this error
E: failed to mount /efs (invalid argument)
i cannot mount efs and i dont have backup of it
searching google told me its got corrupted efs and i find some methods and i tried them not work for me or i didnot understand them correctly.
because i am a noob
so guys help me how to solve this problem

pleas pleas pleas


thanks