Add extra validation when reading dessign matrix

src/ert/config/design_matrix.py

@@ -129,23 +129,26 @@ def read_design_matrix(
         # Read the parameter names (first row) as strings to prevent pandas from modifying them.
         # This ensures that duplicate or empty column names are preserved exactly as they appear in the Excel sheet.
         # By doing this, we can properly validate variable names, including detecting duplicates or missing names.
-        param_names = (
-            pd.read_excel(
+        try:
+            param_names = (
+                pd.read_excel(
+                    self.xls_filename,
+                    sheet_name=self.design_sheet,
+                    nrows=1,
+                    header=None,
+                    dtype="string",
+                )
+                .iloc[0]
+                .apply(lambda x: x.strip() if isinstance(x, str) else x)
+            )
+            design_matrix_df = DesignMatrix._read_excel(
                 self.xls_filename,
-                sheet_name=self.design_sheet,
-                nrows=1,
+                self.design_sheet,
                 header=None,
-                dtype="string",
+                skiprows=1,
             )
-            .iloc[0]
-            .apply(lambda x: x.strip() if isinstance(x, str) else x)
-        )
-        design_matrix_df = DesignMatrix._read_excel(
-            self.xls_filename,
-            self.design_sheet,
-            header=None,
-            skiprows=1,
-        )
+        except (ValueError, AttributeError) as exc:
+            raise ValueError(f"Error reading design matrix: {exc}") from exc
         design_matrix_df.columns = param_names.to_list()
 
         if "REAL" in design_matrix_df.columns:

src/ert/gui/simulation/ensemble_experiment_panel.py

@@ -85,25 +85,31 @@ def __init__(
 
         design_matrix = analysis_config.design_matrix
         if design_matrix is not None:
+            design_matrix_err: str = ""
             if design_matrix.design_matrix_df is None:
-                design_matrix.read_design_matrix()
-
-            if design_matrix.active_realizations:
-                self._active_realizations_field.setText(
-                    ActiveRange(design_matrix.active_realizations).rangestring
+                try:
+                    design_matrix.read_design_matrix()
+                except (ValueError, AttributeError) as exc:
+                    design_matrix_err = str(exc)
+            if design_matrix_err:
+                layout.addRow("Design Matrix", QLabel(design_matrix_err))
+            else:
+                if design_matrix.active_realizations:
+                    self._active_realizations_field.setText(
+                        ActiveRange(design_matrix.active_realizations).rangestring
+                    )
+                show_dm_param_button = QPushButton("Show parameters")
+                show_dm_param_button.setObjectName("show-dm-parameters")
+                show_dm_param_button.setMinimumWidth(50)
+
+                button_layout = QHBoxLayout()
+                button_layout.addWidget(show_dm_param_button)
+                button_layout.addStretch()  # Add stretch to push the button to the left
+
+                layout.addRow("Design Matrix", button_layout)
+                show_dm_param_button.clicked.connect(
+                    lambda: self.on_show_dm_params_clicked(design_matrix)
                 )
-            show_dm_param_button = QPushButton("Show parameters")
-            show_dm_param_button.setObjectName("show-dm-parameters")
-            show_dm_param_button.setMinimumWidth(50)
-
-            button_layout = QHBoxLayout()
-            button_layout.addWidget(show_dm_param_button)
-            button_layout.addStretch()  # Add stretch to push the button to the left
-
-            layout.addRow("Design Matrix", button_layout)
-            show_dm_param_button.clicked.connect(
-                lambda: self.on_show_dm_params_clicked(design_matrix)
-            )
 
         self.setLayout(layout)