Simulation fails to run

Hello everybody,

Some strange massage occurs when I try to run my simulation.
All 8 processor directories are available.
Maybe you know some advice.

/*---------------------------------------------------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 3.0.1 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
Build : 3.0.1-d8a290b55d28
Exec : cfdemSolverPiso -parallel
Date : Dec 10 2017
Time : 11:28:28
Host : "boreas"
PID : 16539
[0]
[0]
[0] --> FOAM FATAL ERROR:
[0] "/home/max/DATA2/leyah/Results_CP/2_Simulation/CFD/system/decomposeParDict" specifies 8 processors but job was started with 4 processors.
[0]
FOAM parallel run exiting
[0]
--------------------------------------------------------------------------
MPI_ABORT was invoked on rank 0 in communicator MPI_COMM_WORLD
with errorcode 1.

NOTE: invoking MPI_ABORT causes Open MPI to kill all MPI processes.
You may or may not see output from other processes, depending on
exactly when Open MPI kills them.
--------------------------------------------------------------------------