diff --git a/cpdctrl_gui/ui/main_window.py b/cpdctrl_gui/ui/main_window.py
index b6116f0..714f37f 100644
--- a/cpdctrl_gui/ui/main_window.py
+++ b/cpdctrl_gui/ui/main_window.py
@@ -113,7 +113,7 @@ class MainWindow(QMainWindow):
 
         # LED SCRIPT
         self.w_led_script = LedScriptViewer(LedScript(0))
-        self.w_led_script.model.dataChanged.connect(self._led_script_updated)
+        self.w_led_script.dataChanged.connect(self._led_script_updated)
         self.w_lefttab.addTab(self.w_led_script, "LED Script")
         self.w_measurement_settings.w_led_script.script_changed.connect(self.led_script_load)
 
@@ -256,19 +256,23 @@ class MainWindow(QMainWindow):
         if self.leddev is None:
             raise ValueError("No led control device selected")
 
-        self.topbar.disable_button("meas_start")
-        self.topbar.disable_button("connect_vmdev")
-        self.topbar.disable_button("connect_leddev")
-        self.topbar.disable_button("meas_save")
-        self.topbar.disable_button("meas_load")
-        self.topbar.enable_button("meas_stop")
-        self.w_plot.clear_data()
 
         name = self.w_measurement_settings.get_value("name")
         script = self.w_measurement_settings.get_value("led_script")
         led_script = LedScript(script=script)
         flush_after = self.w_measurement_settings.get_value("flush_after")
         use_buffer = self.w_measurement_settings.get_value("use_buffer")
+        # check if device supports buffer mode
+        if use_buffer and not callable(getattr(self.vmdev, 'buffer_measure', None)):
+            # show warning dialog
+            ret = QMessageBox.warning(self, "Buffer mode not supported", "The selected voltage measurement device does not support the buffer measurement mode.\nClick Ok to continue without buffer measurement mode.", buttons=QMessageBox.StandardButton.Ok|QMessageBox.StandardButton.Cancel, defaultButton=QMessageBox.StandardButton.Ok)
+            if ret == QMessageBox.StandardButton.Ok:
+                log.warning("Device does not support buffer mode, disabling")
+                use_buffer = False
+            else:
+                log.info("Cancelled measurement due to buffer mode not being available")
+                return
+
         max_measurements = self.w_measurement_settings.get_value("max_measurements")
         stop_on_script_end = self.w_measurement_settings.get_value("stop_on_script_end")
         interval = self.w_measurement_settings.get_value("interval")
@@ -280,6 +284,14 @@ class MainWindow(QMainWindow):
 
         log.info(f"Starting measurement with:\n\tinterval = {interval}\n\tflush_after = {flush_after}\n\tuse_buffer = {use_buffer}\n\tmax_measurements = {max_measurements}\n\tstop_on_script_end = {stop_on_script_end}")
 
+        self.topbar.disable_button("meas_start")
+        self.topbar.disable_button("connect_vmdev")
+        self.topbar.disable_button("connect_leddev")
+        self.topbar.disable_button("meas_save")
+        self.topbar.disable_button("meas_load")
+        self.topbar.enable_button("meas_stop")
+        self.w_plot.clear_data()
+
         # have the led script member be the only auto-updating script,
         # and pass a non-updating copy to the measurement thread
         if self.led_script is None:
@@ -456,6 +468,7 @@ class MainWindow(QMainWindow):
         """
         Send the new led script to the measurement thread and update the gui widget.
         """
+        print("Update script")
         # update gui
         self.w_led_script.update_time_predictions()
         # update the measurement led script