Documentation: add troubleshooting section related to the model (#139)

* add troubleshooting section related to the model

* fix

* Add set_dynamic_available_results_capability in doc

* Update the PR looking at the review that have been made on a similar PR on pydpf-post

Author: anslpa

docs/source/user_guide/troubleshooting.rst

@@ -3,7 +3,7 @@
 ===============
 Troubleshooting
 ===============
-This section explains how to resolve the most common issues encountered with ``pydpf-core``.
+This section explains how to resolve the most common issues encountered with PyDPF-Core.
 It also includes suggestions for improving scripts.
 
 Using the Server
@@ -19,13 +19,13 @@ the environment variable ``AWP_ROOT{VER}`` is set, where VER=212, 221, ....
 
 Connecting to DPF Server
 ~~~~~~~~~~~~~~~~~~~~~~~~
-If an issue appears while using the pydpf-core API to connect to an initialized server with :py:meth:`connect_to_server()
+If an issue appears while using the ``pydpf-core`` API to connect to an initialized server with :py:meth:`connect_to_server()
 <ansys.dpf.core.server.connect_to_server>`, ensure that the IP address and port number that are set as parameters
 are applicable for a DPF server started on the network.
 
 Importing pydpf-core module
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
-Assume that you are importing the pydpf-core module:
+Assume that you are importing the ``pydpf-core`` module:
 
 .. code-block:: default
 
@@ -35,12 +35,41 @@ If an error lists missing modules, see the compatibility paragraph of :ref:`_ref
 The module `ansys.grpc.dpf <https://pypi.org/project/ansys-grpc-dpf/>`_ should always be synchronized with its server
 version.
 
+Using the Model
+---------------
+
+Invalid UTF-8 Error
+~~~~~~~~~~~~~~~~~~~
+Assume that you are trying to access the py:class:`Model<ansys.dpf.core.model.Model>`.
+The following error can be raised:
+
+.. code-block:: default
+
+    [libprotobuf ERROR C:\.conan\897de8\1\protobuf\src\google\protobuf\wire_format_lite.cc:578] 
+    String field 'ansys.api.dpf.result_info.v0.ResultInfoResponse.user_name' contains invalid UTF-8 
+    data when serializing a protocol buffer. Use the 'bytes' type if you intend to send raw bytes.
+
+This will prevent the model from being accessed. To avoid a this error, ensure that you are using
+a PyDPF-Core version higher than 0.3.2. In this case, a warning will still be raised, but it should not 
+prevent the use of the Model. 
+
+Then, with result files reproducing this issue, to avoid the warning to pop up, you can use:
+
+.. code-block:: default
+
+    from ansys.dpf import core as dpf
+    dpf.settings.set_dynamic_available_results_capability(False)
+	
+However, this will disable the reading and generation of the available results of the model: static prewritten 
+available results will be used instead.
+
+
 
 Performance Issues
 ------------------
 
 Getting and Setting a Field's Data
-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 Accessing or modifying field data :py:class:`Field<ansys.dpf.core.field.Field>` entity by entity can
 be slow if the field's size is large or if the server is far from the Python client. To improve performance,
 use :py:meth:`as_local_field()<ansys.dpf.core.field.Field.as_local_field>` in a context manager.