From cba8ff270c901b6786980a0d16a0f0ccddae93f9 Mon Sep 17 00:00:00 2001
From: Leon Friedrich <60421075+ElectroJr@users.noreply.github.com>
Date: Mon, 20 Jun 2022 13:26:21 +1200
Subject: [PATCH] Fix weightless system error (#8965)

---
 .../Gravity/EntitySystems/WeightlessSystem.cs       | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/Content.Server/Gravity/EntitySystems/WeightlessSystem.cs b/Content.Server/Gravity/EntitySystems/WeightlessSystem.cs
index 7d7e549cba..88da9b10c7 100644
--- a/Content.Server/Gravity/EntitySystems/WeightlessSystem.cs
+++ b/Content.Server/Gravity/EntitySystems/WeightlessSystem.cs
@@ -53,8 +53,8 @@ namespace Content.Server.Gravity.EntitySystems
 
         public void RemoveAlert(AlertsComponent status)
         {
-            var grid = EntityManager.GetComponent<TransformComponent>(status.Owner).GridID;
-            if (!_alerts.TryGetValue(grid, out var statuses))
+            var grid = EntityManager.GetComponent<TransformComponent>(status.Owner).GridUid;
+            if (grid == null || !_alerts.TryGetValue(grid.Value, out var statuses))
             {
                 return;
             }
@@ -112,10 +112,13 @@ namespace Content.Server.Gravity.EntitySystems
             if (ev.Transform.MapID == MapId.Nullspace)
                 return;
 
-            var newGrid = ev.Transform.GridID;
-            var newStatuses = _alerts.GetOrNew(newGrid);
 
-            newStatuses.Add(status);
+            var newGrid = ev.Transform.GridUid;
+            if (newGrid != null)
+            {
+                var newStatuses = _alerts.GetOrNew(newGrid.Value);
+                newStatuses.Add(status);
+            }
 
             // then update the actual alert. The alert is only removed if either the player is on a grid with gravity,
             // or if they ignore gravity-based movement altogether.