diff --git a/gui_support/app/EDFMAppController.m b/gui_support/app/EDFMAppController.m
index c6486bc..0fad940 100644
--- a/gui_support/app/EDFMAppController.m
+++ b/gui_support/app/EDFMAppController.m
@@ -1527,7 +1527,8 @@ classdef EDFMAppController < handle
             try
                 uialert(obj.App.UIFigure, message, titleText, varargin{:});
             catch
-                errordlg(obj.formatDialogMessage(message), obj.formatDialogMessage(titleText), 'modal');
+                dialogTitle = obj.formatDialogMessage(titleText);
+                errordlg(obj.formatDialogMessage(message), dialogTitle, 'modal');
             end
         end
 
diff --git a/gui_support/app/EDFMGuideComponent.m b/gui_support/app/EDFMGuideComponent.m
index 50ec11b..3ca33c6 100644
--- a/gui_support/app/EDFMGuideComponent.m
+++ b/gui_support/app/EDFMGuideComponent.m
@@ -2,7 +2,7 @@ classdef EDFMGuideComponent < handle
     %EDFMGUIDECOMPONENT Compatibility adapter from GUIDE/uicontrol to App Designer-style properties.
 
     properties (Constant, Access = private)
-        NUMERIC_FIELD_TYPE = 'numeric'
+        NumericFieldType = 'numeric'
     end
 
     properties (SetAccess = private)
@@ -33,11 +33,13 @@ classdef EDFMGuideComponent < handle
     properties (Access = private)
         StoredMajorTicks = []
         StoredMinorTicks = []
+        IsNumericEditField logical = false
     end
 
     methods
         function obj = EDFMGuideComponent(handleObj)
             obj.Handle = handleObj;
+            obj.IsNumericEditField = obj.detectNumericEditField();
         end
 
         function value = get.Value(obj)
@@ -62,7 +64,7 @@ classdef EDFMGuideComponent < handle
                     if obj.isNumericEditField()
                         value = str2double(string(get(obj.Handle, 'String')));
                         if isnan(value)
-                            value = [];
+                            value = NaN;
                         end
                     else
                         raw = get(obj.Handle, 'String');
@@ -280,8 +282,12 @@ classdef EDFMGuideComponent < handle
         end
 
         function tf = isNumericEditField(obj)
+            tf = obj.IsNumericEditField;
+        end
+
+        function tf = detectNumericEditField(obj)
             userData = get(obj.Handle, 'UserData');
-            tf = isstruct(userData) && isfield(userData, 'Type') && strcmp(userData.Type, obj.NUMERIC_FIELD_TYPE);
+            tf = isstruct(userData) && isfield(userData, 'Type') && strcmp(userData.Type, obj.NumericFieldType);
         end
     end