diff --git a/source/ubl-settings-system.c b/source/ubl-settings-system.c
index 3f6dd54..5b30f2a 100644
--- a/source/ubl-settings-system.c
+++ b/source/ubl-settings-system.c
@@ -383,16 +383,18 @@ void on_console_font_changed(GtkComboBox *self, main_window *widgets){
 
 void on_language_changed(GtkComboBox *self, main_window *widgets){
     GtkTreeIter iter, child;
-    gtk_combo_box_get_active_iter(self,&iter);
-    char *code;
+    if (gtk_combo_box_get_active_iter(self,&iter)){
+        char *code;
 
-    gtk_tree_model_filter_convert_iter_to_child_iter(GTK_TREE_MODEL_FILTER(main_config.localefilter),&child,&iter);
-    gtk_tree_model_get(GTK_TREE_MODEL(widgets->languagelist),&child,1,&code,-1);
-    if (code)
-    if (yon_config_get_by_key(language_parameter)){
-        yon_config_set(language_parameter,code);
-    } else {
-        yon_config_register(language_parameter,LANG_get_command,code);
+        gtk_tree_model_filter_convert_iter_to_child_iter(GTK_TREE_MODEL_FILTER(main_config.localefilter),&child,&iter);
+        gtk_tree_model_get(GTK_TREE_MODEL(widgets->languagelist),&child,1,&code,-1);
+        if (code){
+            if (yon_config_get_by_key(language_parameter)){
+                yon_config_set(language_parameter,code);
+            } else {
+                yon_config_register(language_parameter,LANG_get_command,code);
+            }
+        }
     }
 }
 
diff --git a/source/ubl-strings.h b/source/ubl-strings.h
index 475adde..068b7f5 100644
--- a/source/ubl-strings.h
+++ b/source/ubl-strings.h
@@ -48,6 +48,8 @@
 #define OFF_AUTOMATICALLY_LABEL _("Switch client off or automatically")
 #define INFO_LABEL _("Domain information")
 #define INFO_TITLE_LABEL _("Current domain information")
+#define KERBEROS_TOOLTIP_LABEL _("DNS server that resolves the Kerberos/AD server name")
+#define DNS_TOOLTIP_LABEL _("Full DNS name or IP address")
 #define CONNECTION_LABEL _("Connect to domain")
 #define DDISCONNECTION_LABEL _("Disconnect from domain")
 #define CHECK_NAME_LABEL _("Check domain name")
diff --git a/ubl-settings-system-connection.glade b/ubl-settings-system-connection.glade
index 0e03510..6c3d0fc 100644
--- a/ubl-settings-system-connection.glade
+++ b/ubl-settings-system-connection.glade
@@ -255,6 +255,7 @@
                               <object class="GtkEntry" id="KerberosServerEntry">
                                 <property name="visible">True</property>
                                 <property name="can-focus">True</property>
+                                <property name="tooltip-text" translatable="yes">DNS server that resolves the Kerberos/AD server name</property>
                               </object>
                               <packing>
                                 <property name="expand">True</property>
@@ -290,6 +291,7 @@
                               <object class="GtkEntry" id="DNSEntry">
                                 <property name="visible">True</property>
                                 <property name="can-focus">True</property>
+                                <property name="tooltip-text" translatable="yes">Full DNS name or IP address</property>
                               </object>
                               <packing>
                                 <property name="expand">True</property>