diff --git a/libs/Dashboard/DashboardEngine.m b/libs/Dashboard/DashboardEngine.m
index 2849a48d..07f54b5b 100644
--- a/libs/Dashboard/DashboardEngine.m
+++ b/libs/Dashboard/DashboardEngine.m
@@ -2016,10 +2016,13 @@ function refreshActivePageWidgetsAfterResize_(obj)
                 return;
             end
             ws = obj.activePageWidgets();
+            isOctave = exist('OCTAVE_VERSION', 'builtin') ~= 0;
             % --- Pass 1: cheap data re-push ---
             for i = 1:numel(ws)
                 w = ws{i};
-                if isempty(w) || ~isvalid(w)
+                % Octave 7+ has no isvalid() for classdef handles, so treat
+                % as valid there and rely on downstream guards / try-catch.
+                if isempty(w) || (~isOctave && ~isvalid(w))
                     continue;
                 end
                 if ~w.Realized || isempty(w.hPanel) || ~ishandle(w.hPanel)
@@ -2042,10 +2045,10 @@ function refreshActivePageWidgetsAfterResize_(obj)
             stillWhite = false;
             for i = 1:numel(ws)
                 w = ws{i};
-                if isempty(w) || ~isvalid(w) || ~isa(w, 'FastSenseWidget')
+                if isempty(w) || (~isOctave && ~isvalid(w)) || ~isa(w, 'FastSenseWidget')
                     continue;
                 end
-                if isempty(w.FastSenseObj) || ~isvalid(w.FastSenseObj) || ~w.FastSenseObj.IsRendered
+                if isempty(w.FastSenseObj) || (~isOctave && ~isvalid(w.FastSenseObj)) || ~w.FastSenseObj.IsRendered
                     continue;
                 end
                 if ~obj.isWidgetLineWhite_(w)
diff --git a/libs/Dashboard/DashboardLayout.m b/libs/Dashboard/DashboardLayout.m
index a2e90370..5e1c72e4 100644
--- a/libs/Dashboard/DashboardLayout.m
+++ b/libs/Dashboard/DashboardLayout.m
@@ -1035,7 +1035,10 @@ function syncYLimitButtonsState_(bar, mode)
             inactiveBg = [];
             if isfield(ud, 'YLimitWidget') && ~isempty(ud.YLimitWidget)
                 w = ud.YLimitWidget;
-                if isobject(w) && isvalid(w) && ...
+                % Octave 7+ has no isvalid() for classdef handles; treat as
+                % valid there and rely on the property-access guards below.
+                isOctave = exist('OCTAVE_VERSION', 'builtin') ~= 0;
+                if isobject(w) && (isOctave || isvalid(w)) && ...
                         ~isempty(w.ParentTheme) && isstruct(w.ParentTheme) && ...
                         isfield(w.ParentTheme, 'ToolbarBackground')
                     inactiveBg = w.ParentTheme.ToolbarBackground;
diff --git a/libs/Dashboard/FastSenseWidget.m b/libs/Dashboard/FastSenseWidget.m
index 77c093a7..50d644ce 100644
--- a/libs/Dashboard/FastSenseWidget.m
+++ b/libs/Dashboard/FastSenseWidget.m
@@ -450,7 +450,11 @@ function autoScaleY_(obj, y)
             if obj.UserZoomedY
                 return;
             end
-            if ~isempty(obj.FastSenseObj) && isvalid(obj.FastSenseObj) && ...
+            % Octave 7+ has no isvalid() for classdef handles, so treat the
+            % FastSense handle as valid there and let downstream property
+            % access surface real failures.
+            isOctave = exist('OCTAVE_VERSION', 'builtin') ~= 0;
+            if ~isempty(obj.FastSenseObj) && (isOctave || isvalid(obj.FastSenseObj)) && ...
                     strcmp(obj.FastSenseObj.LiveViewMode, 'follow')
                 return;
             end