diff --git a/bec_widgets/widgets/dap/dap_combo_box/dap_combo_box.py b/bec_widgets/widgets/dap/dap_combo_box/dap_combo_box.py
index 5931d672..10979628 100644
--- a/bec_widgets/widgets/dap/dap_combo_box/dap_combo_box.py
+++ b/bec_widgets/widgets/dap/dap_combo_box/dap_combo_box.py
@@ -65,8 +65,10 @@ class DapComboBox(BECWidget, QWidget):
         """
         if self._validate_dap_model(default_fit):
             self.select_fit_model(default_fit)
-        else:
+        elif self._validate_dap_model("GaussianModel"):
             self.select_fit_model("GaussianModel")
+        elif self.available_models:
+            self.select_fit_model(self.available_models[0])
 
     @property
     def available_models(self):
@@ -154,7 +156,8 @@ class DapComboBox(BECWidget, QWidget):
     def populate_fit_model_combobox(self):
         """Populate the fit_model_combobox with the devices."""
         # pylint: disable=protected-access
-        self.available_models = [model for model in self.client.dap._available_dap_plugins.keys()]
+        available_plugins = getattr(getattr(self.client, "dap", None), "_available_dap_plugins", {})
+        self.available_models = [model for model in available_plugins.keys()]
         self.fit_model_combobox.clear()
         self.fit_model_combobox.addItems(self.available_models)
 
diff --git a/tests/unit_tests/test_dap_combobox.py b/tests/unit_tests/test_dap_combobox.py
index 93cdfca0..b4854ff3 100644
--- a/tests/unit_tests/test_dap_combobox.py
+++ b/tests/unit_tests/test_dap_combobox.py
@@ -71,3 +71,13 @@ def test_dap_combobox_currentTextchanged(dap_combobox):
     dap_combobox.fit_model_updated.connect(my_callback)
     dap_combobox.fit_model_combobox.setCurrentText("SineModel")
     assert container[0] == "SineModel"
+
+
+def test_dap_combobox_init_without_available_models(qtbot, mocked_client):
+    mocked_client.dap._available_dap_plugins = {}
+
+    widget = create_widget(qtbot, DapComboBox, client=mocked_client)
+
+    assert widget.available_models == []
+    assert widget.fit_model_combobox.count() == 0
+    assert widget.fit_model_combobox.currentText() == ""