diff --git a/src/slic3r/GUI/PartSkipDialog.hpp b/src/slic3r/GUI/PartSkipDialog.hpp
index d8c7282710..4137a476fc 100644
--- a/src/slic3r/GUI/PartSkipDialog.hpp
+++ b/src/slic3r/GUI/PartSkipDialog.hpp
@@ -155,4 +155,4 @@ private:
     void OnApplyDialog(wxCommandEvent &event);
 };
 
-}} // namespace Slic3r::GUI
+}} // namespace Slic3r::GUI
\ No newline at end of file
diff --git a/src/slic3r/Utils/IPrinterAgent.hpp b/src/slic3r/Utils/IPrinterAgent.hpp
index d869e56ba6..08e72aa906 100644
--- a/src/slic3r/Utils/IPrinterAgent.hpp
+++ b/src/slic3r/Utils/IPrinterAgent.hpp
@@ -197,8 +197,12 @@ public:
      */
     virtual std::string get_local_file_transfer_url(const FileTransferURLParams& params) { return ""; }
 
-    virtual int get_file_transfer_url(std::string, std::function<void(FileTransferURLResult)>, FileTransferURLParams)
-    { return ORCA_NETWORK_ERR_CMD_NOT_SUPPORTED; }
+    virtual int get_file_transfer_url(std::string, std::function<void(FileTransferURLResult)> callback, FileTransferURLParams)
+    {
+        if (callback)
+            callback({});
+        return ORCA_NETWORK_ERR_CMD_NOT_SUPPORTED;
+    }
 
     /**
      * Default LAN account username for this agent's protocol, if it has a fixed one.
diff --git a/src/slic3r/Utils/NetworkAgent.cpp b/src/slic3r/Utils/NetworkAgent.cpp
index 7598408e25..62a2e21f51 100644
--- a/src/slic3r/Utils/NetworkAgent.cpp
+++ b/src/slic3r/Utils/NetworkAgent.cpp
@@ -873,6 +873,8 @@ int NetworkAgent::get_file_transfer_url(std::string dev_id, std::function<void(F
 {
     if (m_printer_agent)
         return m_printer_agent->get_file_transfer_url(std::move(dev_id), std::move(callback), std::move(params));
+    if (callback)
+        callback({});
     return -1;
 }