diff --git a/src/apprt/gtk/App.zig b/src/apprt/gtk/App.zig
index fba7bf89e..2505810ef 100644
--- a/src/apprt/gtk/App.zig
+++ b/src/apprt/gtk/App.zig
@@ -11,6 +11,7 @@
 const App = @This();
 
 const std = @import("std");
+const assert = std.debug.assert;
 const builtin = @import("builtin");
 const glfw = @import("glfw");
 const configpkg = @import("../../config.zig");
@@ -20,6 +21,7 @@ const CoreSurface = @import("../../Surface.zig");
 
 const Surface = @import("Surface.zig");
 const Window = @import("Window.zig");
+const ConfigErrorsWindow = @import("ConfigErrorsWindow.zig");
 const c = @import("c.zig");
 
 const log = std.log.scoped(.gtk);
@@ -35,6 +37,9 @@ ctx: *c.GMainContext,
 /// The "none" cursor. We use one that is shared across the entire app.
 cursor_none: ?*c.GdkCursor,
 
+/// The configuration errors window, if it is currently open.
+config_errors_window: ?*ConfigErrorsWindow = null,
+
 /// This is set to false when the main loop should exit.
 running: bool = true,
 
@@ -80,7 +85,7 @@ pub fn init(core_app: *CoreApp, opts: Options) !App {
     _ = c.g_signal_connect_data(
         app,
         "activate",
-        c.G_CALLBACK(&activate),
+        c.G_CALLBACK(&gtkActivate),
         core_app,
         null,
         c.G_CONNECT_DEFAULT,
@@ -155,9 +160,31 @@ pub fn reloadConfig(self: *App) !?*const Config {
     self.config.deinit();
     self.config = config;
 
+    // If there were errors, report them
+    self.updateConfigErrors() catch |err| {
+        log.warn("error handling configuration errors err={}", .{err});
+    };
+
     return &self.config;
 }
 
+/// This should be called whenever the configuration changes to update
+/// the state of our config errors window. This will show the window if
+/// there are new configuration errors and hide the window if the errors
+/// are resolved.
+fn updateConfigErrors(self: *App) !void {
+    if (!self.config._errors.empty()) {
+        if (self.config_errors_window == null) {
+            try ConfigErrorsWindow.create(self);
+            assert(self.config_errors_window != null);
+        }
+    }
+
+    if (self.config_errors_window) |window| {
+        window.update();
+    }
+}
+
 /// Called by CoreApp to wake up the event loop.
 pub fn wakeup(self: App) void {
     _ = self;
@@ -166,6 +193,14 @@ pub fn wakeup(self: App) void {
 
 /// Run the event loop. This doesn't return until the app exits.
 pub fn run(self: *App) !void {
+    if (!self.running) return;
+
+    // On startup, we want to check for configuration errors right away
+    // so we can show our error window.
+    self.updateConfigErrors() catch |err| {
+        log.warn("error handling configuration errors err={}", .{err});
+    };
+
     while (self.running) {
         _ = c.g_main_context_iteration(self.ctx, 1);
 
@@ -286,7 +321,7 @@ fn gtkQuitConfirmation(
 /// This is called by the "activate" signal. This is sent on program
 /// startup and also when a secondary instance launches and requests
 /// a new window.
-fn activate(app: *c.GtkApplication, ud: ?*anyopaque) callconv(.C) void {
+fn gtkActivate(app: *c.GtkApplication, ud: ?*anyopaque) callconv(.C) void {
     _ = app;
 
     const core_app: *CoreApp = @ptrCast(@alignCast(ud orelse return));
diff --git a/src/apprt/gtk/ConfigErrorsWindow.zig b/src/apprt/gtk/ConfigErrorsWindow.zig
new file mode 100644
index 000000000..f582c459a
--- /dev/null
+++ b/src/apprt/gtk/ConfigErrorsWindow.zig
@@ -0,0 +1,201 @@
+/// Configuration errors window.
+const ConfigErrors = @This();
+
+const std = @import("std");
+const Allocator = std.mem.Allocator;
+const configpkg = @import("../../config.zig");
+const Config = configpkg.Config;
+
+const App = @import("App.zig");
+const View = @import("View.zig");
+const c = @import("c.zig");
+
+const log = std.log.scoped(.gtk);
+
+app: *App,
+window: *c.GtkWindow,
+view: PrimaryView,
+
+pub fn create(app: *App) !void {
+    if (app.config_errors_window != null) return error.InvalidOperation;
+
+    const alloc = app.core_app.alloc;
+    const self = try alloc.create(ConfigErrors);
+    errdefer alloc.destroy(self);
+    try self.init(app);
+
+    app.config_errors_window = self;
+}
+
+pub fn update(self: *ConfigErrors) void {
+    if (self.app.config._errors.empty()) {
+        c.gtk_window_destroy(@ptrCast(self.window));
+        return;
+    }
+
+    self.view.update(&self.app.config);
+    _ = c.gtk_window_present(self.window);
+    _ = c.gtk_widget_grab_focus(@ptrCast(self.window));
+}
+
+/// Not public because this should be called by the GTK lifecycle.
+fn destroy(self: *ConfigErrors) void {
+    const alloc = self.app.core_app.alloc;
+    self.app.config_errors_window = null;
+    alloc.destroy(self);
+}
+
+fn init(self: *ConfigErrors, app: *App) !void {
+    // Create the window
+    const window = c.gtk_application_window_new(app.app);
+    const gtk_window: *c.GtkWindow = @ptrCast(window);
+    errdefer c.gtk_window_destroy(gtk_window);
+    c.gtk_window_set_title(gtk_window, "Configuration Errors");
+    c.gtk_window_set_default_size(gtk_window, 600, 275);
+    c.gtk_window_set_resizable(gtk_window, 0);
+    _ = c.g_signal_connect_data(window, "destroy", c.G_CALLBACK(&gtkDestroy), self, null, c.G_CONNECT_DEFAULT);
+
+    // Set some state
+    self.* = .{
+        .app = app,
+        .window = gtk_window,
+        .view = undefined,
+    };
+
+    // Show the window
+    const view = try PrimaryView.init(self);
+    self.view = view;
+    c.gtk_window_set_child(@ptrCast(window), view.root);
+    c.gtk_widget_show(window);
+}
+
+fn gtkDestroy(_: *c.GtkWidget, ud: ?*anyopaque) callconv(.C) void {
+    const self = userdataSelf(ud.?);
+    self.destroy();
+}
+
+fn userdataSelf(ud: *anyopaque) *ConfigErrors {
+    return @ptrCast(@alignCast(ud));
+}
+
+const PrimaryView = struct {
+    root: *c.GtkWidget,
+    text: *c.GtkTextView,
+
+    pub fn init(root: *ConfigErrors) !PrimaryView {
+        // All our widgets
+        const label = c.gtk_label_new(
+            "One or more configuration errors were found while loading " ++
+                "the configuration. Please review the errors below and reload " ++
+                "your configuration or ignore the erroneous lines.",
+        );
+        const buf = contentsBuffer(&root.app.config);
+        defer c.g_object_unref(buf);
+        const buttons = try ButtonsView.init(root);
+        const text_scroll = c.gtk_scrolled_window_new();
+        errdefer c.g_object_unref(text_scroll);
+        const text = c.gtk_text_view_new_with_buffer(buf);
+        errdefer c.g_object_unref(text);
+        c.gtk_scrolled_window_set_child(@ptrCast(text_scroll), text);
+
+        // Create our view
+        const view = try View.init(&.{
+            .{ .name = "label", .widget = label },
+            .{ .name = "text", .widget = text_scroll },
+            .{ .name = "buttons", .widget = buttons.root },
+        }, &vfl);
+        errdefer view.deinit();
+
+        // We can do additional settings once the layout is setup
+        c.gtk_label_set_wrap(@ptrCast(label), 1);
+        c.gtk_text_view_set_editable(@ptrCast(text), 0);
+        c.gtk_text_view_set_cursor_visible(@ptrCast(text), 0);
+        c.gtk_text_view_set_top_margin(@ptrCast(text), 8);
+        c.gtk_text_view_set_bottom_margin(@ptrCast(text), 8);
+        c.gtk_text_view_set_left_margin(@ptrCast(text), 8);
+        c.gtk_text_view_set_right_margin(@ptrCast(text), 8);
+
+        return .{ .root = view.root, .text = @ptrCast(text) };
+    }
+
+    pub fn update(self: *PrimaryView, config: *const Config) void {
+        const buf = contentsBuffer(config);
+        defer c.g_object_unref(buf);
+        c.gtk_text_view_set_buffer(@ptrCast(self.text), buf);
+    }
+
+    /// Returns the GtkTextBuffer for the config errors that we want to show.
+    fn contentsBuffer(config: *const Config) *c.GtkTextBuffer {
+        const buf = c.gtk_text_buffer_new(null);
+        errdefer c.g_object_unref(buf);
+
+        for (config._errors.list.items) |err| {
+            c.gtk_text_buffer_insert_at_cursor(buf, err.message, @intCast(err.message.len));
+            c.gtk_text_buffer_insert_at_cursor(buf, "\n", -1);
+        }
+
+        return buf;
+    }
+
+    const vfl = [_][*:0]const u8{
+        "H:|-8-[label]-8-|",
+        "H:|[text]|",
+        "H:|[buttons]|",
+        "V:|[label(<=80)][text(>=100)]-[buttons]-|",
+    };
+};
+
+const ButtonsView = struct {
+    root: *c.GtkWidget,
+
+    pub fn init(root: *ConfigErrors) !ButtonsView {
+        const ignore_button = c.gtk_button_new_with_label("Ignore");
+        errdefer c.g_object_unref(ignore_button);
+
+        const reload_button = c.gtk_button_new_with_label("Reload Configuration");
+        errdefer c.g_object_unref(reload_button);
+
+        // Create our view
+        const view = try View.init(&.{
+            .{ .name = "ignore", .widget = ignore_button },
+            .{ .name = "reload", .widget = reload_button },
+        }, &vfl);
+
+        // Signals
+        _ = c.g_signal_connect_data(
+            ignore_button,
+            "clicked",
+            c.G_CALLBACK(&gtkIgnoreClick),
+            root,
+            null,
+            c.G_CONNECT_DEFAULT,
+        );
+        _ = c.g_signal_connect_data(
+            reload_button,
+            "clicked",
+            c.G_CALLBACK(&gtkReloadClick),
+            root,
+            null,
+            c.G_CONNECT_DEFAULT,
+        );
+
+        return .{ .root = view.root };
+    }
+
+    fn gtkIgnoreClick(_: *c.GtkWidget, ud: ?*anyopaque) callconv(.C) void {
+        const self: *ConfigErrors = @ptrCast(@alignCast(ud));
+        c.gtk_window_destroy(@ptrCast(self.window));
+    }
+
+    fn gtkReloadClick(_: *c.GtkWidget, ud: ?*anyopaque) callconv(.C) void {
+        const self: *ConfigErrors = @ptrCast(@alignCast(ud));
+        _ = self.app.reloadConfig() catch |err| {
+            log.warn("error reloading config error={}", .{err});
+            return;
+        };
+    }
+
+    const vfl = [_][*:0]const u8{
+        "H:[ignore]-8-[reload]-8-|",
+    };
+};
diff --git a/src/apprt/gtk/View.zig b/src/apprt/gtk/View.zig
new file mode 100644
index 000000000..2287b4737
--- /dev/null
+++ b/src/apprt/gtk/View.zig
@@ -0,0 +1,73 @@
+/// View helps with creating a view with a constraint layout by
+/// managing all the boilerplate. The caller is responsible for
+/// providing the widgets, their names, and the VFL code and gets
+/// a root box as a result ready to be used.
+const View = @This();
+
+const std = @import("std");
+const c = @import("c.zig");
+
+const log = std.log.scoped(.gtk);
+
+/// The box that contains all of the widgets.
+root: *c.GtkWidget,
+
+/// A single widget used in the view.
+pub const Widget = struct {
+    /// The name of the widget used for the layout code. This is also
+    /// the name set for the widget for CSS styling.
+    name: [:0]const u8,
+
+    /// The widget itself.
+    widget: *c.GtkWidget,
+};
+
+/// Initialize a new constraint layout view with the given widgets
+/// and VFL.
+pub fn init(widgets: []const Widget, vfl: []const [*:0]const u8) !View {
+    // Box to store all our widgets
+    const box = c.gtk_box_new(c.GTK_ORIENTATION_VERTICAL, 0);
+    errdefer c.g_object_unref(box);
+    c.gtk_widget_set_vexpand(box, 1);
+    c.gtk_widget_set_hexpand(box, 1);
+
+    // Setup our constraint layout and attach it to the box
+    const layout = c.gtk_constraint_layout_new();
+    errdefer c.g_object_unref(layout);
+    c.gtk_widget_set_layout_manager(@ptrCast(box), layout);
+
+    // Setup our views table
+    const views = c.g_hash_table_new(c.g_str_hash, c.g_str_equal);
+    defer c.g_hash_table_unref(views);
+
+    // Add our widgets
+    for (widgets) |widget| {
+        c.gtk_widget_set_parent(widget.widget, box);
+        c.gtk_widget_set_name(widget.widget, widget.name);
+        _ = c.g_hash_table_insert(
+            views,
+            @constCast(@ptrCast(widget.name.ptr)),
+            widget.widget,
+        );
+    }
+
+    // Add all of our constraints for layout
+    var err_: ?*c.GError = null;
+    const list = c.gtk_constraint_layout_add_constraints_from_descriptionv(
+        @ptrCast(layout),
+        vfl.ptr,
+        vfl.len,
+        8,
+        8,
+        views,
+        &err_,
+    );
+    if (err_) |err| {
+        defer c.g_error_free(err);
+        log.warn("error building view message={s}", .{err.message});
+        return error.OperationFailed;
+    }
+    c.g_list_free(list);
+
+    return .{ .root = box };
+}