Added checks for character removal to a bunch of places. Some of these may not necessary, but at least MeleeWeapon, Projectile and Controller still accessed the user after the user had been removed.

Barotrauma/BarotraumaShared/Source/Items/Components/Holdable/MeleeWeapon.cs

@@ -52,7 +52,7 @@ namespace Barotrauma.Items.Components
 
         public override bool Use(float deltaTime, Character character = null)
         {
-            if (character == null || reloadTimer>0.0f) return false;
+            if (character == null || reloadTimer > 0.0f) return false;
             if (!character.IsKeyDown(InputType.Aim) || hitting) return false;
 
             //don't allow hitting if the character is already hitting with another weapon
@@ -172,6 +172,7 @@ namespace Barotrauma.Items.Components
         private void SetUser(Character character)
         {
             if (user == character) return;
+            if (user != null && user.Removed) user = null;
 
             if (user != null)
             {
@@ -213,6 +214,13 @@ namespace Barotrauma.Items.Components
 
         private bool OnCollision(Fixture f1, Fixture f2, Contact contact)
         {
+            if (user == null || user.Removed)
+            {
+                RestoreCollision();
+                hitting = false;
+                user = null;
+            }
+
             Character targetCharacter = null;
             Limb targetLimb = null;
             Structure targetStructure = null;