ScaLAPACK crash using different block sizes

Hi,

I would like to use pzgesv routine to solve system of linear equations but it crashes if use block size 64 and e.g. with two processes  

it doesn't crash if i run the program with mpirun -np 1 ./myapp, or the block size is 4 and any number of processes. 

number of rows = 116, nrhs = 4; openmpi, mpicxx -v: gcc version 7.4.0 

here is the backtrace:

from the gdb

process 1

Thread 1 "myapp" received signal SIGSEGV, Segmentation fault.
0x00007ffff67483b2 in PMPI_Comm_size ()
   from /usr/lib/x86_64-linux-gnu/libmpi.so.20
(gdb) bt 
#0  0x00007ffff67483b2 in PMPI_Comm_size ()
   from /usr/lib/x86_64-linux-gnu/libmpi.so.20
#1  0x000055555897967a in MKLMPI_Comm_size ()
#2  0x000055555568884c in PB_CpgemmMPI ()
#3  0x000055555564e916 in pzgemm_ ()
#4  0x00005555556355b0 in pzgetrf2_ ()
#5  0x0000555555634aaf in pzgetrf_ ()
#6  0x000055555562c60d in pzgesv_ ()
#7  0x00005555555ed944 in main (argc=1, argv=0x7fffffffd6e8)
    at Main.cpp:159

process 0

Thread 1 "myapp" received signal SIGSEGV, Segmentation fault.
0x00007ffff67483b2 in PMPI_Comm_size ()
   from /usr/lib/x86_64-linux-gnu/libmpi.so.20
(gdb) bt
#0  0x00007ffff67483b2 in PMPI_Comm_size ()
   from /usr/lib/x86_64-linux-gnu/libmpi.so.20
#1  0x000055555897967a in MKLMPI_Comm_size ()
#2  0x000055555568884c in PB_CpgemmMPI ()
#3  0x000055555564e916 in pzgemm_ ()
#4  0x00005555556355b0 in pzgetrf2_ ()
#5  0x0000555555634aaf in pzgetrf_ ()
#6  0x000055555562c60d in pzgesv_ ()
#7  0x00005555555ed944 in main (argc=1, argv=0x7fffffffd6e8)
    at Main.cpp:159

the descriptors and data looks OK.

any idea what is going on?

Regards,

sk