# Step 6: Error 4

## Error Message

```{code-block} pyrejournal
---
caption: Error message 4 when running Step 6.
linenos: True
emphasize-lines: 68-69
---
$ pylith step06_twofaults.cfg

# Output
 >> software/pylith-debug/lib/python3.12/site-packages/pylith/apps/PyLithApp.py:76:main
 -- info (application-flow)
 -- Running on 1 process(es).
 >> src/cig/pylith/libsrc/pylith/utils/PetscOptions.cc:251:static void pylith::utils::_PetscOptions::write(pythia::journal::info_t &, const char *, const PetscOptions &)
 -- info (application-flow)
 -- Setting PETSc options:
    dm_reorder_section = true
    dm_reorder_section_type = cohesive
    ksp_atol = 1.0e-7
    ksp_converged_reason = true
    ksp_error_if_not_converged = true
    ksp_gmres_restart = 100
    ksp_guess_pod_size = 8
    ksp_guess_type = pod
    ksp_rtol = 1.0e-14
    mg_fine_ksp_max_it = 5
    mg_fine_pc_type = vpbjacobi
    pc_type = gamg
    snes_atol = 5.0e-7
    snes_converged_reason = true
    snes_error_if_not_converged = true
    snes_monitor = true
    snes_rtol = 1.0e-14
    ts_error_if_step_fails = true
    ts_exact_final_time = matchstep
    ts_monitor = true
    ts_type = beuler
    viewer_hdf5_collective = true

 >> src/cig/pylith/libsrc/pylith/meshio/MeshIOPetsc.cc:205:virtual void pylith::meshio::MeshIOPetsc::_read()
 -- info (application-flow)
 -- Component 'meshiopetsc.reader': Reading finite-element mesh from 'mesh_tri.msh'.
 >> src/cig/pylith/libsrc/pylith/meshio/MeshIO.cc:76:void pylith::meshio::MeshIO::read(pylith::topology::Mesh *, const bool)
 -- info (application-flow)
 -- Component 'meshiopetsc.reader': Domain bounding box:
    (-100000, 100000)
    (-100000, 0)
 >> src/cig/pylith/libsrc/pylith/initializers/MeshInsertInterfaces.cc:51:virtual pylith::topology::Mesh *pylith::initializers::MeshInsertInterfaces::run(pylith::topology::Mesh *, const pylith::problems::Problem &)
 -- info (application-flow)
 -- Inserting cohesive cells.
 >> src/cig/pylith/libsrc/pylith/problems/TimeDependent.cc:316:virtual void pylith::problems::TimeDependent::verifyConfiguration() const
 -- info (application-flow)
 -- Component 'timedependent.problem': Verifying problem configuration.
 >> software/pylith-debug/lib/python3.12/site-packages/pylith/problems/Problem.py:238:_printInfo
 -- info (application-flow)
 -- Scales for nondimensionalization:
    Length scale: 2500*m
    Displacement scale: 1*m
    Time scale: 3.15576e+09*s
    Rigidity scale: 1e+10*m**-1*kg*s**-2
    Temperature scale: 1*K
 >> src/cig/pylith/libsrc/pylith/problems/TimeDependent.cc:342:virtual void pylith::problems::TimeDependent::initialize()
 -- info (application-flow)
 -- Component 'timedependent.problem': Initializing problem.
Fatal error. Calling MPI_Abort() to abort PyLith application.
Traceback (most recent call last):
  File "software/pylith-debug/lib/python3.12/site-packages/pylith/apps/PetscApplication.py", line 55, in onComputeNodes
    self.main(*args, **kwds)
  File "software/pylith-debug/lib/python3.12/site-packages/pylith/apps/PyLithApp.py", line 85, in main
    self.problem.initialize()
  File "software/pylith-debug/lib/python3.12/site-packages/pylith/problems/Problem.py", line 212, in initialize
    ModuleProblem.initialize(self)
  File "software/pylith-debug/lib/python3.12/site-packages/pylith/problems/problems.py", line 165, in initialize
    return _problems.Problem_initialize(self)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
RuntimeError: Error occurred while reading spatial database file 'fault_slip.spatialdb'.
Read data for 3 out of 4 points.
Error reading coordinates from buffer ''.
Abort(-1) on node 0 (rank 0 in comm 0): application called MPI_Abort(MPI_COMM_WORLD, -1) - process 0
software/pylith-debug/bin/nemesis: mpiexec: exit 255
software/pylith-debug/bin/pylith: software/pylith-debug/bin/nemesis: exit 1
```

## Troubleshooting Strategy

The error message on lines 97-98 indicates there is an error reading the `fault_slip.spatialdb` spatial database for the fault slip.
PyLith was able to read data for 3 of 4 points.
The file `fault_slip.spatialdb` contains only 3 points but `num-locs` is 4.

## Resolution

```{code-block} cfg
---
caption: Correct error in `fault_slip.spatialdb`.
---
# Error
num-locs = 4

# Correct
num-locs = 3
```