From f2c1070f95980f488fb67823fcffa595b704896b Mon Sep 17 00:00:00 2001
From: Viktor Liu <17948409+lixmal@users.noreply.github.com>
Date: Wed, 29 Jul 2026 20:52:18 +0900
Subject: [PATCH] [client] Fix UI crash on Windows builds without dark-mode
 support (#6958)

---
 client/ui/services/windowtheme_windows.go | 14 ++++++++++++++
 1 file changed, 14 insertions(+)
 create mode 100644 client/ui/services/windowtheme_windows.go

diff --git a/client/ui/services/windowtheme_windows.go b/client/ui/services/windowtheme_windows.go
new file mode 100644
index 000000000..7dbc1164b
--- /dev/null
+++ b/client/ui/services/windowtheme_windows.go
@@ -0,0 +1,14 @@
+package services
+
+import "github.com/wailsapp/wails/v3/pkg/w32"
+
+// Wails assigns w32.AllowDarkModeForWindow only on builds >= 18334 but calls it
+// without a nil check when a window requests the Dark theme, crashing older
+// builds such as Windows Server 2019 (17763). Those builds still get a dark
+// title bar via the pre-20H1 DWM attribute that w32.SetTheme applies, so a
+// no-op stub keeps the Dark theme fully working there.
+func init() {
+	if w32.AllowDarkModeForWindow == nil {
+		w32.AllowDarkModeForWindow = func(w32.HWND, bool) uintptr { return 0 }
+	}
+}