--- a\src\win\iupwin_dragdrop.c	Mon Dec 11 14:52:42 2017
+++ b\src\win\iupwin_dragdrop.c	Wed Jan 24 22:52:48 2018
@@ -418,7 +418,10 @@
 
   /* fill data */
   cbDragData = (IFnsVi)IupGetCallback(pThis->ih, "DRAGDATA_CB");
-  cbDragData(pThis->ih, iupwinStrFromSystem(type), pData, size);
+  if (cbDragData)
+  {
+    cbDragData(pThis->ih, iupwinStrFromSystem(type), pData, size);
+  }
 
   GlobalUnlock(pStgMedium->hGlobal);
 
@@ -794,8 +797,6 @@
     lstrcpy(name, TEXT("BITMAP"));
   else if (cf == CF_METAFILEPICT)
     lstrcpy(name, TEXT("METAFILEPICT"));
-  else if (cf == CF_TIFF)
-    lstrcpy(name, TEXT("TIFF"));
   else if (cf == CF_TIFF)
     lstrcpy(name, TEXT("TIFF"));
   else if (cf == CF_DIB)