Index: src/file-manager/fm-properties-window.c
===================================================================
--- src/file-manager/fm-properties-window.c	(revision 14785)
+++ src/file-manager/fm-properties-window.c	(working copy)
@@ -4973,8 +4973,7 @@
 
 	eel_g_list_free_deep (uris);
 
-	ret = key->str;
-	g_string_free (key, FALSE);
+	ret = g_string_free (key, FALSE);
 
 	return ret;
 }
Index: libnautilus-private/nautilus-thumbnails.c
===================================================================
--- libnautilus-private/nautilus-thumbnails.c	(revision 14785)
+++ libnautilus-private/nautilus-thumbnails.c	(working copy)
@@ -467,7 +467,12 @@
 	if (!gdk_pixbuf_loader_close (loader, &error) ||
 	    /* Seems we have to check this even if it returned TRUE (#403255) */
 	    error != NULL) {
-		g_message ("Failed to close thumbnail pixbuf loader for %s: %s", path, error->message);
+		/* In some cases, we don't get an error even with FALSE returns (#538888) */
+		if (error != NULL) {
+			g_message ("Failed to close thumbnail pixbuf loader for %s: %s", path, error->message);
+		} else {
+			g_message ("Failed to close thumbnail pixbuf loader for %s", path);
+		}
 
 		g_object_unref (G_OBJECT (loader));
 		g_error_free (error);
