# Step 1: Error 1

## Error Message

```{code-block} console
---
caption: Error message 1 when running Step 1.
linenos: True
emphasize-lines: 3-6
---
$ pylith step01a_gravity.cfg

 >> {default}::
 -- error (pyre.inventory)
 -- timedependent.problem_defaults.name <- ''
 -- Missing required property 'name' in default options for problem.
 >> {default}::
 -- error (pyre.inventory)
 -- timedependent.bc.dirichlettimedependent.label <- ''
 -- Label for boundary condition group/nodeset/pset in mesh not specified.
 >> {default}::
 -- error (pyre.inventory)
 -- timedependent.bc.dirichlettimedependent.simpledb.description <- ''
 -- Description for spatial database not specified.
 >> {default}::
 -- error (pyre.inventory)
 -- timedependent.bc.dirichlettimedependent.simpledb.simpleioascii.filename <- ''
 -- Filename for spatial database not specified.
 >> {default}::
 -- error (pyre.inventory)
 -- timedependent.bc.dirichlettimedependent.constrained_dof <- '[]'
 -- No constrained degrees of freedom found for time-dependent Dirichlet boundary condition 'bc_xpos'. 'constrained_dof' must be a zero-based integer array (0=x, 1=y, 2=z).
 >> ./pylithapp.cfg:112:
 -- error (pyre.inventory)
 -- pylithapp.timedependent.materials.elasticity.auxiliary_subfields.bulk_modulus.basis_order <- '0'
 -- unknown component 'pylithapp.timedependent.materials.elasticity.auxiliary_subfields.bulk_modulus'
 >> ./pylithapp.cfg:113:
 -- error (pyre.inventory)
 -- pylithapp.timedependent.materials.elasticity.auxiliary_subfields.shear_modulus.basis_order <- '0'
 -- unknown component 'pylithapp.timedependent.materials.elasticity.auxiliary_subfields.shear_modulus'
 >> ./pylithapp.cfg:135:
 -- error (pyre.inventory)
 -- pylithapp.timedependent.bc.xpos.label <- 'boundary_xpos'
 -- unknown component 'pylithapp.timedependent.bc.xpos'
 >> ./pylithapp.cfg:136:
 -- error (pyre.inventory)
 -- pylithapp.timedependent.bc.xpos.label_value <- '11'
 -- unknown component 'pylithapp.timedependent.bc.xpos'
 >> ./pylithapp.cfg:137:
 -- error (pyre.inventory)
 -- pylithapp.timedependent.bc.xpos.constrained_dof <- '[0]'
 -- unknown component 'pylithapp.timedependent.bc.xpos'
 >> ./pylithapp.cfg:138:
 -- error (pyre.inventory)
 -- pylithapp.timedependent.bc.xpos.db_auxiliary_field <- 'pylith.bc.ZeroDB'
 -- unknown component 'pylithapp.timedependent.bc.xpos'
 >> ./pylithapp.cfg:139:
 -- error (pyre.inventory)
 -- pylithapp.timedependent.bc.xpos.db_auxiliary_field.description <- 'Dirichlet BC +x edge'
 -- unknown component 'pylithapp.timedependent.bc.xpos.db_auxiliary_field'
 >> ./pylithapp.cfg:141:
 -- error (pyre.inventory)
 -- pylithapp.timedependent.bc.xpos.auxiliary_subfields.initial_amplitude.basis_order <- '0'
 -- unknown component 'pylithapp.timedependent.bc.xpos.auxiliary_subfields.initial_amplitude'
usage: pylith [--<property>=<value>] [--<facility>.<property>=<value>] [FILE.cfg] ...
component 'pylithapp'
    properties: dump_parameters, help, help-components, help-persistence, help-properties, include-citations, initialize_only, job, launcher, metadata, nodes, petsc, problem, scheduler, show_application_flow, start_python_debugger, typos, weaver
    facilities: dump_parameters,job,launcher,metadata,petsc,problem,scheduler,weaver
For more information:
  --help-properties: prints details about user settable properties
  --help-components: prints details about user settable facilities and components
pylithapp: configuration error(s)

```

## Troubleshooting Strategy

The full error message shows several errors associated with our parameter files.
Because errors often cascade, the best place to start is to address the first error (lines 3-6).
We see that the default name for `problem_defaults` is empty and PyLith requires one.
This name will be used as the first part of the filename for output.
We resolve this error by examining the parameters for `pylithapp.timedependent.problem_defaults` in `step01_gravity.cfg`.
We see that we do not set any of the problem defaults.

## Resolution

We must set the simulation name in the problem defaults.

```{code-block} cfg
---
caption: Correct error in `step01a_gravity.cfg`.
---
[pylithapp]
...
# Set the name of the problem that will be used to construct the
# output filenames. The default directory for output is 'output'.
problem.defaults.name = step01a_gravity
```