diff --git a/cms/api.py b/cms/api.py
index 97609f06..541f27d2 100644
--- a/cms/api.py
+++ b/cms/api.py
@@ -68,7 +68,7 @@ from cms.utils.i18n import get_language_list
 from cms.utils.page import get_available_slug, get_clean_username
 from cms.utils.permissions import get_current_user, reset_current_user, set_current_user
 from cms.utils.plugins import copy_plugins_to_placeholder, downcast_plugins
-from .menus.menu_pool import menu_pool
+from menus.menu_pool import menu_pool
 
 # ===============================================================================
 # Helpers/Internals
diff --git a/datacenterlight/cms_models.py b/datacenterlight/cms_models.py
index 6d27a71d..abe9d312 100644
--- a/datacenterlight/cms_models.py
+++ b/datacenterlight/cms_models.py
@@ -307,30 +307,35 @@ class DCLSectionPromoPluginModel(CMSPlugin):
 class MultipleChoiceArrayField(ArrayField):
     """
     A field that allows us to store an array of choices.
+
     Uses Django's Postgres ArrayField
     and a MultipleChoiceField for its formfield.
     """
-    VMTemplateChoices = []
-    if settings.OPENNEBULA_DOMAIN != 'test_domain':
-        VMTemplateChoices = list(
-            (
-                str(obj.opennebula_vm_template_id),
-                (obj.name + ' - ' + VMTemplate.IPV6.title()
-                    if obj.vm_type == VMTemplate.IPV6 else obj.name
-                 )
-             )
-            for obj in VMTemplate.objects.all()
-        )
 
     def formfield(self, **kwargs):
+        vm_template_choices = []
+
+        if settings.OPENNEBULA_DOMAIN != 'test_domain':
+            vm_template_choices = [
+                (
+                    str(obj.opennebula_vm_template_id),
+                    (
+                        obj.name + ' - ' + VMTemplate.IPV6.title()
+                        if obj.vm_type == VMTemplate.IPV6
+                        else obj.name
+                    ),
+                )
+                for obj in VMTemplate.objects.all()
+            ]
+
         defaults = {
             'form_class': forms.MultipleChoiceField,
-            'choices': self.VMTemplateChoices,
+            'choices': vm_template_choices,
         }
+
         defaults.update(kwargs)
-        # Skip our parent's formfield implementation completely as we don't
-        # care for it.
-        # pylint:disable=bad-super-call
+
+        # Skip ArrayField.formfield() because we don't need its implementation.
         return super(ArrayField, self).formfield(**defaults)
 
 
diff --git a/dynamicweb/settings/base.py b/dynamicweb/settings/base.py
index d5088827..3e62b85d 100644
--- a/dynamicweb/settings/base.py
+++ b/dynamicweb/settings/base.py
@@ -120,7 +120,7 @@ INSTALLED_APPS = (
     #TODO'aldryn_translation_tools',
     'treebeard',  # utilities for implementing a tree
     'sekizai',  # for javascript and css management
-    #TODO'menus',  # helper for model independent hierarchical website navigation
+    'menus',  # helper for model independent hierarchical website navigation
     #TODO'cmsplugin_filer_image',
 
     # 2nd migrate
diff --git a/legacy_compat.py b/legacy_compat.py
index e4a78b63..13b8970a 100644
--- a/legacy_compat.py
+++ b/legacy_compat.py
@@ -492,4 +492,32 @@ def legacy_charfield_init(self, *args, **kwargs):
     _original_charfield_init(self, **kwargs)
 
 
-forms.CharField.__init__ = legacy_charfield_init
\ No newline at end of file
+forms.CharField.__init__ = legacy_charfield_init
+
+
+
+import sys
+import types
+from collections.abc import (
+    MutableSequence,
+    MutableMapping,
+    MutableSet,
+    Sequence,
+    Mapping,
+    Set,
+)
+
+
+def install_backport_collections_shim():
+    module = types.ModuleType("backport_collections")
+
+    module.MutableSequence = MutableSequence
+    module.MutableMapping = MutableMapping
+    module.MutableSet = MutableSet
+    module.Sequence = Sequence
+    module.Mapping = Mapping
+    module.Set = Set
+
+    sys.modules["backport_collections"] = module
+
+install_backport_collections_shim()
\ No newline at end of file
diff --git a/opennebula_api/serializers.py b/opennebula_api/serializers.py
index 34cdde7c..faa0d894 100644
--- a/opennebula_api/serializers.py
+++ b/opennebula_api/serializers.py
@@ -43,6 +43,7 @@ class VirtualMachineTemplateSerializer(serializers.Serializer):
 
 
 class VirtualMachineSerializer(serializers.Serializer):
+
     """Serializer to map the virtual machine instance into JSON format."""
 
     name = serializers.SerializerMethodField()
@@ -50,7 +51,6 @@ class VirtualMachineSerializer(serializers.Serializer):
     disk = serializers.IntegerField(write_only=True)
     set_memory = serializers.IntegerField(write_only=True, label='Memory')
     memory = serializers.SerializerMethodField()
-
     disk_size = serializers.SerializerMethodField()
     hdd_size = serializers.SerializerMethodField()
     ssd_size = serializers.SerializerMethodField()
@@ -63,14 +63,20 @@ class VirtualMachineSerializer(serializers.Serializer):
     configuration = serializers.SerializerMethodField()
 
     template_id = serializers.ChoiceField(
-        choices=[(key.id, key.name) for key in
-                 OpenNebulaManager().try_get_templates()
-                 ],
+        choices=[],
         source='template.template_id',
         write_only=True,
-        default=[]
+        default=[],
     )
 
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+
+        self.fields['template_id'].choices = [
+            (key.id, key.name)
+            for key in OpenNebulaManager().try_get_templates()
+        ]
+
     def create(self, validated_data):
         owner = validated_data['owner']
         ssh_key = validated_data['ssh_key']