From 29d6420ecc2187db951f08dd47289277a11f4db5 Mon Sep 17 00:00:00 2001
From: Amit Miran <47772523+amitmiran137@users.noreply.github.com>
Date: Wed, 24 Feb 2021 12:08:28 +0200
Subject: [PATCH] fix: exception when saving dash (#13300)

* fix: project None value

* fix: pre-commit
---
 superset/views/core.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/superset/views/core.py b/superset/views/core.py
index 155555e4a..2c390c406 100755
--- a/superset/views/core.py
+++ b/superset/views/core.py
@@ -1178,7 +1178,10 @@ class Superset(BaseSupersetView):  # pylint: disable=too-many-public-methods
         # the dashboard was open. it was use to avoid mid-air collision.
         remote_last_modified_time = data.get("last_modified_time")
         current_last_modified_time = dash.changed_on.replace(microsecond=0).timestamp()
-        if remote_last_modified_time < current_last_modified_time:
+        if (
+            remote_last_modified_time
+            and remote_last_modified_time < current_last_modified_time
+        ):
             return json_error_response(
                 __(
                     "This dashboard was changed recently. "