diff --git a/deluge/ui/gtkui/addtorrentdialog.py b/deluge/ui/gtkui/addtorrentdialog.py
index a108b1e6a..bd7db2f1a 100644
--- a/deluge/ui/gtkui/addtorrentdialog.py
+++ b/deluge/ui/gtkui/addtorrentdialog.py
@@ -352,7 +352,9 @@ class AddTorrentDialog(component.Component):
                     _file, _file['path'], idx, _file.get('download', True), split_files
                 )
             self.add_files(None, split_files)
-        self.listview_files.expand_row(b'0', False)
+        # FIXME add back expand_row
+        # self.listview_files.expand_row(b'0', False)
+        self.listview_files.expand_all()
 
     def prepare_file(self, _file, file_name, file_num, download, files_storage):
         first_slash_index = file_name.find(os.path.sep)
@@ -1043,7 +1045,9 @@ class AddTorrentDialog(component.Component):
 
                 # We need to re-expand the view because it might contracted
                 # if we change the root iter
-                self.listview_files.expand_row(b'0', False)
+                # FIXME add back expand_row
+                # self.listview_files.expand_row('0', False)
+                self.listview_files.expand_all()
             else:
                 # This was a simple folder rename without any splits, so just
                 # change the path for itr
diff --git a/deluge/ui/gtkui/files_tab.py b/deluge/ui/gtkui/files_tab.py
index bfa9c8c46..91a0b480c 100644
--- a/deluge/ui/gtkui/files_tab.py
+++ b/deluge/ui/gtkui/files_tab.py
@@ -379,7 +379,8 @@ class FilesTab(Tab):
     def update_files(self):
         with listview_replace_treestore(self.listview):
             self.prepare_file_store(self.files_list[self.torrent_id])
-        self.listview.expand_row(b'0', False)
+        # FIXME
+        # self.listview.expand_row(b'0', False)
 
     def get_selected_files(self):
         """Returns a list of file indexes that are selected."""
@@ -414,7 +415,8 @@ class FilesTab(Tab):
 
     def update_folder_percentages(self):
         """Go through the tree and update the folder complete percentages."""
-        root = self.treestore.get_iter_root()
+        # FIXME Why changed? Was: self.treestore.get_iter_root()
+        root = self.treestore.get_iter_first()
         if root is None or self.treestore[root][5] != -1:
             return
 
diff --git a/deluge/ui/gtkui/gtkui.py b/deluge/ui/gtkui/gtkui.py
index d3bafe4d9..660e915ad 100644
--- a/deluge/ui/gtkui/gtkui.py
+++ b/deluge/ui/gtkui/gtkui.py
@@ -190,8 +190,11 @@ class GtkUI(object):
         self.queuedtorrents = QueuedTorrents()
         self.ipcinterface = IPCInterface(args.torrents)
 
-        # Initialize gdk threading
-        threads_init()
+        # FIXME: Verify that removing gdk threading has no adverse effects.
+        # There are the two commits [64a94ec] [1f3e930] that added gdk threading
+        # and my thinking is there is no need for the code anymore.
+        # Since PyGObject 3.10.2, calling GObject.threads_init() this is no longer needed.
+        # threads_init()
 
         # We make sure that the UI components start once we get a core URI
         client.set_disconnect_callback(self.__on_disconnect)
diff --git a/deluge/ui/gtkui/listview.py b/deluge/ui/gtkui/listview.py
index 39b390275..ba182a735 100644
--- a/deluge/ui/gtkui/listview.py
+++ b/deluge/ui/gtkui/listview.py
@@ -18,6 +18,7 @@ from gtk.gdk import Event  # pylint: disable=ungrouped-imports
 from deluge.common import decode_bytes
 from deluge.ui.gtkui.common import load_pickled_state_file, save_pickled_state_file
 
+# FIXME: ?
 signal_new(
     'button-press-event', gtk.TreeViewColumn, SIGNAL_RUN_LAST, TYPE_NONE, (Event,)
 )
@@ -41,6 +42,12 @@ class ListViewColumnState:  # pylint: disable=old-style-class
         self.sort_order = sort_order
 
 
+# FIXME: Why is this needed?
+class TreeModel(GObject.Object, Gtk.TreeModel):
+    def __init__(self, filter):
+        Gtk.TreeModel.__init__(self, filter)
+
+
 class ListView(object):
     """ListView is used to make custom GtkTreeViews.  It supports the adding
     and removing of columns, creating a menu for a column toggle list and
@@ -220,7 +227,11 @@ class ListView(object):
             self.last_sort_order = {}
 
             def record_position(model, path, _iter, data):
-                self.last_sort_order[model[_iter][self.unique_column_id]] = path[0]
+                # FIXME: TypeError: 'TreePath' object does not support indexing
+                # Verify (old code: ` = path[0]`)
+                self.last_sort_order[model[_iter][self.unique_column_id]] = int(
+                    str(model.get_path(iter))
+                )
 
             model.foreach(record_position, None)
 
@@ -575,6 +586,7 @@ class ListView(object):
         column.set_min_width(20)
         column.set_reorderable(True)
         column.set_visible(not hidden)
+        # FIXME: Check for errors with button press, related new signal
         column.connect('button-press-event', self.on_treeview_header_right_clicked)
 
         if tooltip:
diff --git a/deluge/ui/gtkui/mainwindow.py b/deluge/ui/gtkui/mainwindow.py
index 1d3668979..b967f7262 100644
--- a/deluge/ui/gtkui/mainwindow.py
+++ b/deluge/ui/gtkui/mainwindow.py
@@ -76,9 +76,8 @@ class MainWindow(component.Component):
         # Think about splitting up  mainwindow gtkbuilder file into the necessary parts
         # to avoid GtkBuilder monkey patch. Those parts would then need adding to mainwindow 'by hand'.
         self.gtk_builder_signals_holder = _GtkBuilderSignalsHolder()
-        self.main_builder.prev_connect_signals = copy.deepcopy(
-            self.main_builder.connect_signals
-        )
+        # FIXME: The deepcopy has been removed: copy.deepcopy(self.main_builder.connect_signals)
+        self.main_builder.prev_connect_signals = self.main_builder.connect_signals
 
         def patched_connect_signals(*a, **k):
             raise RuntimeError(
diff --git a/deluge/ui/gtkui/path_combo_chooser.py b/deluge/ui/gtkui/path_combo_chooser.py
index 7d5c46ffd..bdcaa0654 100755
--- a/deluge/ui/gtkui/path_combo_chooser.py
+++ b/deluge/ui/gtkui/path_combo_chooser.py
@@ -12,9 +12,11 @@ from __future__ import division, print_function, unicode_literals
 
 import os
 
-import gtk
-from gobject import SIGNAL_RUN_FIRST, TYPE_NONE, GObject, type_register
-from gtk import gdk, keysyms  # pylint: disable=ungrouped-imports
+# FIXME: use this as fallback to get_introspection_module?
+from gi.importer import modules
+
+# from gi.module import get_introspection_module
+from gi.repository import Gdk, GObject, Gtk
 
 import deluge.component as component
 from deluge.common import resource_filename
diff --git a/deluge/ui/gtkui/systemtray.py b/deluge/ui/gtkui/systemtray.py
index f54300304..2f3453d49 100644
--- a/deluge/ui/gtkui/systemtray.py
+++ b/deluge/ui/gtkui/systemtray.py
@@ -357,9 +357,8 @@ class SystemTray(component.Component):
         if windows_check() or osx_check():
             popup_function = None
             button = 0
-        self.tray_menu.popup(
-            None, None, popup_function, button, activate_time, status_icon
-        )
+        # FIXME why was status_icon removed??
+        self.tray_menu.popup(None, None, None, popup_function, button, activate_time)
 
     def on_menuitem_show_deluge_activate(self, menuitem):
         log.debug('on_menuitem_show_deluge_activate')
diff --git a/deluge/ui/gtkui/torrentview.py b/deluge/ui/gtkui/torrentview.py
index 05f246a77..f008d0fc4 100644
--- a/deluge/ui/gtkui/torrentview.py
+++ b/deluge/ui/gtkui/torrentview.py
@@ -660,6 +660,7 @@ class TorrentView(ListView, component.Component):
                 to_update = []
                 for i, status_field in fields_to_update:
                     row_value = status[torrent_id][status_field]
+                    # FIXME: Seeing UnicodeWarning??
                     if row[i] != row_value:
                         to_update.append(i)
                         to_update.append(row_value)