I9500 write certificate problem

Hi, i have a problem when i tried to write a certificate in a I9500 with lollipop 5.0.1. When its writting the certficate a error happens, "current imei checksum error". And when the phone restarts it has generic imei 0049 etc.
With other boxes i read that i have to whipe efs first but chimera dont have that option, what i´m doing wrong? Thanks for your help.