Hi, Running another case. I got also a FPE. This is the output of gdb: Program received signal SIGFPE, Arithmetic exception. 0x1204efc4c in VecNorm_MPI (xin=0x120d626d0, type=NORM_2, z=0x11fffe690) at pvec2.c:80 80 work *= work; (gdb) p work $1 = 7.7555804021556748e+161 Billy.