diff --git a/docs/en_US/release_notes_6_15.rst b/docs/en_US/release_notes_6_15.rst
index 43187fa46..bfc2aeb10 100644
--- a/docs/en_US/release_notes_6_15.rst
+++ b/docs/en_US/release_notes_6_15.rst
@@ -25,6 +25,7 @@ Housekeeping
 Bug fixes
 *********
 
+  | `Issue #5145 <https://github.com/pgadmin-org/pgadmin4/issues/5145>`_ -  Fixed intermittent error shown while OAuth2 login.
   | `Issue #5188 <https://github.com/pgadmin-org/pgadmin4/issues/5188>`_ -  Ensure that the continue/start button should be disabled if the user stops the Debugger for the procedures.
   | `Issue #5210 <https://github.com/pgadmin-org/pgadmin4/issues/5210>`_ -  Ensure that the query tool creates a new tab with the appropriate user when pressing Alt+Shift+Q.
   | `Issue #5249 <https://github.com/pgadmin-org/pgadmin4/issues/5249>`_ -  Added the ability to display the selected text from the query tool in the find/replace box.
diff --git a/web/pgadmin/authenticate/__init__.py b/web/pgadmin/authenticate/__init__.py
index a678ec480..2e3a9bb1f 100644
--- a/web/pgadmin/authenticate/__init__.py
+++ b/web/pgadmin/authenticate/__init__.py
@@ -67,12 +67,15 @@ def login():
     The user input will be validated and authenticated.
     """
     form = _security.login_form()
-
-    auth_obj = AuthSourceManager(form, copy.deepcopy(
-        config.AUTHENTICATION_SOURCES))
     if OAUTH2 in config.AUTHENTICATION_SOURCES \
             and 'oauth2_button' in request.form:
+        # Sending empty form as oauth2 does not require form attribute
+        auth_obj = AuthSourceManager({}, copy.deepcopy(
+            config.AUTHENTICATION_SOURCES))
         session['auth_obj'] = auth_obj
+    else:
+        auth_obj = AuthSourceManager(form, copy.deepcopy(
+            config.AUTHENTICATION_SOURCES))
 
     session['auth_source_manager'] = None