diff --git a/addons/netfox/rollback/rollback-synchronizer.gd b/addons/netfox/rollback/rollback-synchronizer.gd
index bcff3176..ed8162ec 100644
--- a/addons/netfox/rollback/rollback-synchronizer.gd
+++ b/addons/netfox/rollback/rollback-synchronizer.gd
@@ -328,7 +328,9 @@ func _ready() -> void:
 	multiplayer.connected_to_server.connect(process_settings)
 
 func _notification(what: int) -> void:
-	if what == NOTIFICATION_EDITOR_PRE_SAVE:
+	if what == NOTIFICATION_PREDELETE:
+		_cleanup()
+	elif what == NOTIFICATION_EDITOR_PRE_SAVE:
 		update_configuration_warnings()
 
 func _get_configuration_warnings() -> PackedStringArray:
@@ -373,15 +375,23 @@ func _exit_tree() -> void:
 	_managed_roots.erase(root)
 
 	if root.is_queued_for_deletion():
-		# RBS and its nodes are being freed, time to deregister everything
-		for node in _sim_nodes + _state_properties.get_subjects() + _input_properties.get_subjects():
-			RollbackSimulationServer.deregister_node(node)
-			NetworkSynchronizationServer.deregister(node)
-			NetworkIdentityServer.deregister_node(node)
-			NetworkHistoryServer.deregister(node)
-
-		for node in _liveness_nodes:
-			RollbackLivenessServer.deregister(node)
+		_cleanup()
+
+func _cleanup() -> void:
+	if _sim_nodes.is_empty():
+		return
+
+	for node in _sim_nodes + _state_properties.get_subjects() + _input_properties.get_subjects():
+		RollbackSimulationServer.deregister_node(node)
+		NetworkSynchronizationServer.deregister(node)
+		NetworkIdentityServer.deregister_node(node)
+		NetworkHistoryServer.deregister(node)
+
+	for node in _liveness_nodes:
+		RollbackLivenessServer.deregister(node)
+
+	_sim_nodes.clear()
+	_liveness_nodes.clear()
 
 func _reprocess_settings() -> void:
 	if not _properties_dirty or Engine.is_editor_hint():
diff --git a/addons/netfox/servers/network-history-server.gd b/addons/netfox/servers/network-history-server.gd
index cce5325f..f1369b16 100644
--- a/addons/netfox/servers/network-history-server.gd
+++ b/addons/netfox/servers/network-history-server.gd
@@ -181,6 +181,9 @@ func _record(tick: int, history: _PerObjectHistory, snapshots: _HistoryBuffer, p
 
 		if _ignored_subjects.has(subject):
 			continue
+		
+		if not subject.is_inside_tree():
+			continue
 
 		var is_auth := auth_filter.call(subject)
 
diff --git a/addons/netfox/servers/rollback-simulation-server.gd b/addons/netfox/servers/rollback-simulation-server.gd
index 40e74adb..85c0d3c0 100644
--- a/addons/netfox/servers/rollback-simulation-server.gd
+++ b/addons/netfox/servers/rollback-simulation-server.gd
@@ -116,6 +116,13 @@ func simulate(delta: float, tick: int) -> void:
 
 	# Determine predicted nodes
 	for node in _callbacks.keys():
+		if not is_instance_valid(node):
+			_callbacks.erase(node)
+			continue
+		
+		if not node.is_inside_tree():
+			continue
+		
 		if _is_predicting(input_snapshot, node):
 			_predicted_nodes.add(node)