diff --git a/includes/ingest.form.inc b/includes/ingest.form.inc
index c285c5a1..e2e97d5f 100644
--- a/includes/ingest.form.inc
+++ b/includes/ingest.form.inc
@@ -31,8 +31,15 @@
  *   The form definition of the current step.
  */
 function islandora_ingest_form(array $form, array &$form_state, array $configuration) {
-  islandora_ingest_form_init_form_state_storage($form_state, $configuration);
-  return islandora_ingest_form_execute_step($form, $form_state);
+  try {
+    islandora_ingest_form_init_form_state_storage($form_state, $configuration);
+    return islandora_ingest_form_execute_step($form, $form_state);
+  }
+  catch(Exception $e) {
+    drupal_set_message($e->getMessage(), 'error');
+    return array(array(
+        '#markup' => l(t('Back'), 'javascript:window.history.back();', array('external' => TRUE))));
+  }
 }
 
 /**
@@ -42,21 +49,16 @@ function islandora_ingest_form(array $form, array &$form_state, array $configura
  *
  * @todo Add hook for manipulating/validating the configuration.
  *
+ * @see islandora_ingest_form()
+ *
  * @throws InvalidArgumentException
  *
  * @param array $configuration
  *   The key value pairs that are used to build the multi-paged ingest process.
- *
- * @see islandora_ingest_form()
- *
- * @return bool
- *   TRUE if the configuration is valid, FALSE otherwise.
  */
-function islandora_ingest_form_validiate_configuration(array $configuration) {
+function islandora_ingest_form_validate_configuration(array $configuration) {
   if (empty($configuration['models'])) {
-    $message = t('Ingest configuration not vaild, no models were given');
-    drupal_set_message($message, 'error');
-    throw new InvalidArgumentException($message);
+    throw new InvalidArgumentException('Ingest configuration not vaild, no models were given');
   }
 }
 
@@ -71,8 +73,8 @@ function islandora_ingest_form_validiate_configuration(array $configuration) {
  */
 function islandora_ingest_form_init_form_state_storage(array &$form_state, array $configuration) {
   if (empty($form_state['islandora'])) {
-    // Validate the configuration before using it.
-    islandora_ingest_form_validiate_configuration($configuration);
+    // Validate the configuration before we use it.
+    islandora_ingest_form_validate_configuration($configuration);
     $object = islandora_ingest_form_prepare_new_object($configuration);
     $form_state['islandora'] = array(
       'step_id' => NULL,
@@ -233,12 +235,19 @@ function islandora_ingest_form_decrement_step(array &$form_state) {
  *   The list of key/value pairs of configuration.
  */
 function islandora_ingest_get_approximate_steps(array $configuration) {
-  $fake_form_state = array(
+  try {
+    islandora_ingest_form_validate_configuration($configuration);
+  }
+  catch(InvalidArgumentException $e) {
+    // Don't log or display exception.
+    return array();
+  }
+  $stubbed_form_state = array(
     'islandora' => array(
       'shared_storage' => $configuration,
     ),
   );
-  $steps = islandora_ingest_form_get_steps($fake_form_state);
+  $steps = islandora_ingest_form_get_steps($stubbed_form_state);
   drupal_static_reset('islandora_ingest_form_get_steps');
   return $steps;
 }
diff --git a/includes/utilities.inc b/includes/utilities.inc
index 3efb6f28..f061f72c 100644
--- a/includes/utilities.inc
+++ b/includes/utilities.inc
@@ -79,6 +79,19 @@ function islandora_is_valid_pid($pid) {
   return drupal_strlen(trim($pid)) <= 64 && preg_match('/^([A-Za-z0-9]|-|\.)+:(([A-Za-z0-9])|-|\.|~|_|(%[0-9A-F]{2}))+$/', trim($pid));
 }
 
+/**
+ * Checks if the given namespace is valid.
+ *
+ * @param string $namespace
+ *   The namespace to check without the ":" character.
+ *
+ * @return bool
+ *   TRUE if valid, FALSE otherwise.
+ */
+function islandora_is_valid_namespace($namespace) {
+  return drupal_strlen(trim($namespace)) <= 64 && preg_match('/^([A-Za-z0-9]|-|\.)+$/', trim($namespace));
+}
+
 /**
  * Checks if the given datastream id is valid.
  *
@@ -673,3 +686,55 @@ function islandora_user_access_any(array $perms, $account = NULL) {
   }
   return FALSE;
 }
+
+/**
+ * Gets the list of allowed namespaces as defined by 'islandora_pids_allowed'.
+ *
+ * @return array
+ *   The list of namespaces striped of trailing ":" characters.
+ */
+function islandora_get_allowed_namespaces() {
+  $matches = array();
+  $allowed_namespaces = variable_get('islandora_pids_allowed', 'default: demo: changeme: islandora:');
+  preg_match_all('/([A-Za-z0-9-\.]+):/', $allowed_namespaces, $matches);
+  return $matches[1];
+}
+
+/**
+ * Gets a list of all existing content models.
+ *
+ * If 'islandora_namespace_restriction_enforced' is set to true only return
+ * content models in the allowed namespace.
+ *
+ * @param bool $ignore_system_namespace
+ *   Ignore content models in the 'fedora-system' namespace.
+ *
+ * @return array
+ *   An associative array of all existing content models.
+ *   - pid: The PID of the content model object.
+ *     - pid: The PID of the content model object.
+ *     - label: The label of the content model object.
+ */
+function islandora_get_content_models($ignore_system_namespace = TRUE) {
+  module_load_include('inc', 'islandora', 'includes/utilities');
+  $tuque = islandora_get_tuque_connection();
+  $query = 'select $object $label from <#ri>
+          where ($object <fedora-model:label> $label
+          and ($object <fedora-model:hasModel> <info:fedora/fedora-system:ContentModel-3.0>
+          or $object <fedora-rels-ext:isMemberOfCollection> <info:fedora/islandora:ContentModelsCollection>)
+          and $object <fedora-model:state> <info:fedora/fedora-system:def/model#Active>)
+          order by $label';
+  $content_models = array();
+  $results = $tuque->repository->ri->itqlQuery($query, 'unlimited');
+  foreach ($results as $result) {
+    $content_model = $result['object']['value'];
+    $label = $result['label']['value'];
+    $namespace = islandora_get_namespace($content_model);
+    $ignore = $ignore_system_namespace && $namespace == 'fedora-system';
+    $ignore |= !islandora_namespace_accessible($namespace);
+    if (!$ignore) {
+      $content_models[$content_model] = array('pid' => $content_model, 'label' => $label);
+    }
+  }
+  return $content_models;
+}