diff --git a/web/pgadmin/browser/server_groups/servers/__init__.py b/web/pgadmin/browser/server_groups/servers/__init__.py
index feeb2e5af..a34b92840 100644
--- a/web/pgadmin/browser/server_groups/servers/__init__.py
+++ b/web/pgadmin/browser/server_groups/servers/__init__.py
@@ -1266,8 +1266,17 @@ class ServerNode(PGChildNodeView):
                     ).format(arg)
                 )
 
-        connection_params = convert_connection_parameter(
-            data.get('connection_params', []))
+        # convert_connection_parameter() is bidirectional: list->dict for
+        # save (frontend shape), dict->list for display (DB shape). Here
+        # we want the storage shape (dict). If the input is already a
+        # dict (e.g. from internal callers / tests that mimic stored
+        # form), keep it as-is; otherwise assume frontend list shape and
+        # convert.
+        raw_params = data.get('connection_params', [])
+        if isinstance(raw_params, dict):
+            connection_params = raw_params
+        else:
+            connection_params = convert_connection_parameter(raw_params)
 
         if 'hostaddr' in connection_params and \
                 not is_valid_ipaddress(connection_params['hostaddr']):
diff --git a/web/pgadmin/misc/workspaces/__init__.py b/web/pgadmin/misc/workspaces/__init__.py
index afb20b5e8..a5ae5c662 100644
--- a/web/pgadmin/misc/workspaces/__init__.py
+++ b/web/pgadmin/misc/workspaces/__init__.py
@@ -93,8 +93,14 @@ def adhoc_connect_server():
                 ).format(arg)
             )
 
-    connection_params = convert_connection_parameter(
-        data.get('connection_params', []))
+    # convert_connection_parameter() is bidirectional. For a save path we
+    # want the storage shape (dict). If the input is already a dict, keep
+    # it; otherwise assume frontend list shape and convert.
+    raw_params = data.get('connection_params', [])
+    if isinstance(raw_params, dict):
+        connection_params = raw_params
+    else:
+        connection_params = convert_connection_parameter(raw_params)
 
     if connection_params is not None:
         if 'hostaddr' in connection_params and \
diff --git a/web/pgadmin/tools/user_management/__init__.py b/web/pgadmin/tools/user_management/__init__.py
index 52497d4b3..d7d3946c8 100644
--- a/web/pgadmin/tools/user_management/__init__.py
+++ b/web/pgadmin/tools/user_management/__init__.py
@@ -168,7 +168,7 @@ def user(uid):
                                'username': u.username,
                                'email': u.email,
                                'active': u.active,
-                               'role': u.roles[0].id,
+                               'role': u.roles[0].id if u.roles else None,
                                'auth_source': u.auth_source,
                                'locked': u.locked,
                                'canDrop': u.id != current_user.id
diff --git a/web/pgadmin/utils/preferences.py b/web/pgadmin/utils/preferences.py
index ace5f7c28..06ea7ab55 100644
--- a/web/pgadmin/utils/preferences.py
+++ b/web/pgadmin/utils/preferences.py
@@ -197,8 +197,8 @@ class _Preference():
                                   if 'value' in opt and opt['value'] == value),
                                  False)
                 assert (has_value or (self.control_props and
-                                      (self.control_props['tags'] or
-                                       self.control_props['creatable'])))
+                                      (self.control_props.get('tags') or
+                                       self.control_props.get('creatable'))))
             elif self._type == 'date':
                 value = parser_map[self._type](value).date()
             else:
diff --git a/web/pgadmin/utils/validation_utils.py b/web/pgadmin/utils/validation_utils.py
index fec586951..fb6994fbf 100644
--- a/web/pgadmin/utils/validation_utils.py
+++ b/web/pgadmin/utils/validation_utils.py
@@ -13,6 +13,12 @@ from email_validator import validate_email as email_validate, \
 
 
 def validate_email(email, email_config=None):
+    # email_validator raises TypeError (not EmailNotValidError) when the
+    # input is not str/bytes. Treat anything non-string as invalid so
+    # callers see a clean False, matching the contract that this wrapper
+    # never raises.
+    if not isinstance(email, (str, bytes)):
+        return False
     try:
         if email_config is None:
             email_config = {}