g_warning() is a printf-like function and its first argument should

be a format string.

--- src/mainwindow.c

+++ src/mainwindow.c

@@ -634,7 +634,7 @@

   /* create the open file thread */

   if(g_thread_create(open_torrent_file, filename, FALSE, &err) == NULL)

   {

-    g_warning(err->message);

+    g_warning("%s", err->message);

     g_free(filename);

     g_error_free(err);

   } 

@@ -671,7 +671,7 @@

   if(g_thread_create(tracker_scrape, tracker, FALSE, &err) == NULL)

   {

-    g_warning(err->message);

+    g_warning("%s", err->message);

     g_free(tracker);

     g_error_free(err);

   } 

@@ -722,7 +722,7 @@

        filename = gtk_file_chooser_get_filename(GTK_FILE_CHOOSER(dialog));

        if(g_thread_create(check_files, filename, FALSE, &err) == NULL)

        {

-         g_warning(err->message);

+         g_warning("%s", err->message);

          g_free(filename); 

          g_error_free(err);

        }

@@ -755,7 +755,7 @@

   if(g_thread_create(tracker_scrape, tracker, FALSE, &err) == NULL)

   {

-    g_warning(err->message);

+    g_warning("%s", err->message);

     g_error_free(err);

   } 

@@ -853,7 +853,7 @@

     {

       if(g_thread_create(open_torrent_file, filename, FALSE, &err) == NULL)

       {

-        g_warning(err->message);

+        g_warning("%s", err->message);

         g_free(filename);

         g_error_free(err);

       }