diff --git a/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/schema_diff_utils.py b/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/schema_diff_utils.py
index 7c3f5e89e..560353dcc 100644
--- a/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/schema_diff_utils.py
+++ b/web/pgadmin/browser/server_groups/servers/databases/schemas/tables/schema_diff_utils.py
@@ -11,9 +11,9 @@
 
 import copy
 
-from flask import render_template
 from pgadmin.utils.driver import get_driver
 from config import PG_DEFAULT_DRIVER
+from pgadmin.utils.ajax import internal_server_error
 from pgadmin.tools.schema_diff.directory_compare import compare_dictionaries,\
     directory_diff
 from pgadmin.tools.schema_diff.model import SchemaDiffModel
diff --git a/web/pgadmin/tools/schema_diff/__init__.py b/web/pgadmin/tools/schema_diff/__init__.py
index 4e3750c53..c71b33297 100644
--- a/web/pgadmin/tools/schema_diff/__init__.py
+++ b/web/pgadmin/tools/schema_diff/__init__.py
@@ -21,7 +21,7 @@ from flask_security import current_user, login_required
 from flask_babelex import gettext
 from pgadmin.utils import PgAdminModule
 from pgadmin.utils.ajax import make_json_response, bad_request, \
-    make_response as ajax_response, not_implemented, internal_server_error
+    make_response as ajax_response, internal_server_error
 from pgadmin.model import Server
 from pgadmin.tools.schema_diff.node_registry import SchemaDiffRegistry
 from pgadmin.tools.schema_diff.model import SchemaDiffModel
@@ -298,6 +298,7 @@ def get_server(sid, did):
     This function will return the server details for the specified
     server id.
     """
+    res = []
     try:
         """Return a JSON document listing the server groups for the user"""
         driver = get_driver(PG_DEFAULT_DRIVER)
diff --git a/web/pgadmin/tools/schema_diff/compare.py b/web/pgadmin/tools/schema_diff/compare.py
index 8d7f681cb..793b204df 100644
--- a/web/pgadmin/tools/schema_diff/compare.py
+++ b/web/pgadmin/tools/schema_diff/compare.py
@@ -12,16 +12,15 @@
 import copy
 
 from flask import render_template
-from pgadmin.utils.compile_template_name import compile_template_path
 from pgadmin.utils.driver import get_driver
 from config import PG_DEFAULT_DRIVER
+from pgadmin.utils.ajax import internal_server_error
 from pgadmin.tools.schema_diff.directory_compare import compare_dictionaries,\
     directory_diff
 from pgadmin.tools.schema_diff.model import SchemaDiffModel
-from abc import abstractmethod
 
 
-class SchemaDiffObjectCompare():
+class SchemaDiffObjectCompare:
 
     keys_to_ignore = ['oid', 'schema']
 
diff --git a/web/pgadmin/tools/schema_diff/directory_compare.py b/web/pgadmin/tools/schema_diff/directory_compare.py
index a7543a789..82a24f0ca 100644
--- a/web/pgadmin/tools/schema_diff/directory_compare.py
+++ b/web/pgadmin/tools/schema_diff/directory_compare.py
@@ -23,6 +23,7 @@ def compare_dictionaries(source_dict, target_dict, node, node_label,
     :param source_dict: First Dictionary
     :param target_dict: Second Dictionary
     :param node: node type
+    :param node_label: node label
     :param ignore_keys: List of keys that will be ignored while comparing
     :return:
     """
@@ -108,6 +109,7 @@ def are_lists_identical(source_list, target_list, ignore_keys):
     This function is used to compare two list.
     :param source_list:
     :param target_list:
+    :param ignore_keys: ignore keys to compare
     :return:
     """
     if source_list is None or target_list is None or \
@@ -132,8 +134,9 @@ def are_dictionaries_identical(source_dict, target_dict, ignore_keys):
     """
     This function is used to recursively compare two dictionaries with
     same keys.
-    :param source_dict:
-    :param target_dict:
+    :param source_dict: source dict
+    :param target_dict: target dict
+    :param ignore_keys: ignore keys to compare
     :return:
     """
 
@@ -187,6 +190,7 @@ def directory_diff(source_dict, target_dict, ignore_keys=[], difference={}):
     :param source_dict: source dict
     :param target_dict: target dict
     :param ignore_keys: ignore keys to compare
+    :param difference:
     """
 
     src_keys = set(source_dict.keys())
@@ -207,9 +211,9 @@ def directory_diff(source_dict, target_dict, ignore_keys=[], difference={}):
         if key in ignore_keys:
             pass
         elif key in tar_only:
-            target_only[key] = target_dict[key]
-            # Target only values in deleted list
-            difference[key]['deleted'] = target_dict[key]
+            if type(target_dict[key]) is list:
+                difference[key] = {}
+                difference[key]['deleted'] = target_dict[key]
         elif key in src_only:
             # Source only values in the newly added list
             if type(source_dict[key]) is list: