diff --git a/CHANGELOG.md b/CHANGELOG.md
index e2f4629900..b991413fb4 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## Unreleased
+
+### Fixed
+
+- Fix error when updating closed modal window in Slack by @vadimkerr ([#2019](https://github.com/grafana/oncall/pull/2019))
+
 ## v1.2.30 (2023-05-25)
 
 ### Fixed
diff --git a/engine/apps/slack/scenarios/resolution_note.py b/engine/apps/slack/scenarios/resolution_note.py
index 72a014e83e..e7316d40a9 100644
--- a/engine/apps/slack/scenarios/resolution_note.py
+++ b/engine/apps/slack/scenarios/resolution_note.py
@@ -13,6 +13,7 @@
 from .step_mixins import CheckAlertIsUnarchivedMixin
 
 logger = logging.getLogger(__name__)
+logger.setLevel(logging.DEBUG)
 
 
 class AddToResolutionNoteStep(CheckAlertIsUnarchivedMixin, scenario_step.ScenarioStep):
@@ -418,12 +419,23 @@ def process_scenario(self, slack_user_identity, slack_team_identity, payload, da
         }
 
         if "update" in resolution_note_window_action:
-            self._slack_client.api_call(
-                "views.update",
-                trigger_id=payload["trigger_id"],
-                view=view,
-                view_id=payload["view"]["id"],
-            )
+            try:
+                self._slack_client.api_call(
+                    "views.update",
+                    trigger_id=payload["trigger_id"],
+                    view=view,
+                    view_id=payload["view"]["id"],
+                )
+            except SlackAPIException as e:
+                if e.response["error"] == "not_found":
+                    # Ignore "not_found" error, it means that the view was closed by user before the update request.
+                    # It doesn't disrupt the user experience.
+                    logger.debug(
+                        f"API call to views.update failed for alert group {alert_group_pk}, error: not_found. "
+                        f"Most likely the view was closed by user before the request was processed. "
+                    )
+                else:
+                    raise
         else:
             self._slack_client.api_call(
                 "views.open",
diff --git a/engine/apps/slack/tests/test_scenario_steps/test_resolution_note.py b/engine/apps/slack/tests/test_scenario_steps/test_resolution_note.py
index 75bf823f18..fb1ac4f3af 100644
--- a/engine/apps/slack/tests/test_scenario_steps/test_resolution_note.py
+++ b/engine/apps/slack/tests/test_scenario_steps/test_resolution_note.py
@@ -1,8 +1,11 @@
 import json
+from unittest.mock import patch
 
 import pytest
 
 from apps.slack.scenarios.scenario_step import ScenarioStep
+from apps.slack.slack_client import SlackClientWithErrorHandling
+from apps.slack.slack_client.exceptions import SlackAPIException
 from common.api_helpers.utils import create_engine_url
 
 
@@ -177,3 +180,37 @@ def test_get_resolution_notes_blocks_latest_limit(
         ]
 
     assert blocks == expected_blocks
+
+
+@pytest.mark.django_db
+@patch.object(
+    SlackClientWithErrorHandling,
+    "api_call",
+    side_effect=SlackAPIException(response={"ok": False, "error": "not_found"}),
+)
+def test_resolution_notes_modal_closed_before_update(
+    mock_slack_api_call, make_organization_and_user_with_slack_identities, make_alert_receive_channel, make_alert_group
+):
+    ResolutionNoteModalStep = ScenarioStep.get_step("resolution_note", "ResolutionNoteModalStep")
+
+    organization, _, slack_team_identity, slack_user_identity = make_organization_and_user_with_slack_identities()
+    organization.refresh_from_db()  # without this there's something weird with organization.archive_alerts_from
+
+    alert_receive_channel = make_alert_receive_channel(organization)
+    alert_group = make_alert_group(alert_receive_channel)
+
+    payload = {
+        "trigger_id": "TEST",
+        "view": {"id": "TEST"},
+        "actions": [
+            {"value": json.dumps({"alert_group_pk": alert_group.pk, "resolution_note_window_action": "update"})}
+        ],
+    }
+
+    # Check that no error is raised even if the Slack API call fails
+    step = ResolutionNoteModalStep(organization=organization, slack_team_identity=slack_team_identity)
+    step.process_scenario(slack_user_identity, slack_team_identity, payload)
+
+    # Check that "views.update" API call was made
+    call_args, _ = mock_slack_api_call.call_args
+    assert call_args[0] == "views.update"