diff --git a/src/main.cpp b/src/main.cpp
index 7147005..3d77720 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -698,6 +698,12 @@ void ShowSelectPopup(HWND owner, int ctrlId, const std::vector<std::wstring>& it
     int h = (int)items.size() * 30 + 6, wdt = (int)anchor.Width;
     HWND p = CreateWindowExW(WS_EX_TOOLWINDOW | WS_EX_TOPMOST, L"DictPopup", L"",
         WS_POPUP, tl.x, tl.y + 2, wdt, h, owner, nullptr, hInst, nullptr);
+    if (!p) {
+        wchar_t dbg[128];
+        swprintf_s(dbg, L"Popup failed: w=%d h=%d x=%d y=%d err=%d", wdt, h, tl.x, tl.y, GetLastError());
+        MessageBoxW(owner, dbg, L"Popup Error", MB_OK);
+        return;
+    }
     int corner = DWMWCP_ROUND; DwmSetWindowAttribute(p, DWMWA_WINDOW_CORNER_PREFERENCE, &corner, sizeof(corner));
     ShowWindow(p, SW_SHOWNA); SetFocus(p);
 }