diff --git a/src/slic3r/GUI/Plater.cpp b/src/slic3r/GUI/Plater.cpp
index bdee81b867..53c3e8a80c 100644
--- a/src/slic3r/GUI/Plater.cpp
+++ b/src/slic3r/GUI/Plater.cpp
@@ -5872,6 +5872,27 @@ std::vector<size_t> Plater::priv::load_files(const std::vector<fs::path>& input_
     if (input_files.empty())
         return std::vector<size_t>();
 
+    // Fusion 360 .f3d cannot be opened: closed Autodesk ShapeManager kernel, no offline reader
+    // exists. Redirect the user to STEP (which we import natively). Skip any .f3d, load the rest.
+    {
+        bool any_f3d = false;
+        for (const auto& p : input_files)
+            if (boost::iends_with(p.string(), ".f3d")) { any_f3d = true; break; }
+        if (any_f3d) {
+            MessageDialog(static_cast<wxWindow*>(q),
+                _L("Fusion 360 .f3d files can't be opened directly — they use Autodesk's "
+                   "closed file format, which no offline tool can read.\n\n"
+                   "In Fusion 360, use File ▸ Export and choose STEP (.step), then open that "
+                   "file here."),
+                _L("Unsupported format: .f3d"), wxOK | wxICON_INFORMATION).ShowModal();
+            std::vector<fs::path> kept;
+            for (const auto& p : input_files)
+                if (!boost::iends_with(p.string(), ".f3d")) kept.push_back(p);
+            if (kept.empty()) return std::vector<size_t>();
+            return load_files(kept, strategy, ask_multi);
+        }
+    }
+
     if (!input_files.empty())
        q->m_3mf_path = input_files[0].string();