diff --git a/blackboard/bb_param/bb_node.cpp b/blackboard/bb_param/bb_node.cpp
index c841193..f7546ef 100644
--- a/blackboard/bb_param/bb_node.cpp
+++ b/blackboard/bb_param/bb_node.cpp
@@ -13,7 +13,7 @@
 
 Variant BBNode::get_value(Node *p_scene_root, const Ref<Blackboard> &p_blackboard, const Variant &p_default) {
 	ERR_FAIL_NULL_V_MSG(p_scene_root, Variant(), "BBNode: get_value() failed - scene_root is null.");
-	ERR_FAIL_NULL_V_MSG(p_blackboard, Variant(), "BBNode: get_value() failed - blackboard is null.");
+	ERR_FAIL_COND_V_MSG(p_blackboard.is_null(), Variant(), "BBNode: get_value() failed - blackboard is null.");
 
 	Variant val;
 	if (get_value_source() == SAVED_VALUE) {
diff --git a/blackboard/blackboard_plan.cpp b/blackboard/blackboard_plan.cpp
index 567e1d9..2f8f02b 100644
--- a/blackboard/blackboard_plan.cpp
+++ b/blackboard/blackboard_plan.cpp
@@ -532,7 +532,7 @@ void BlackboardPlan::populate_blackboard(const Ref<Blackboard> &p_blackboard, bo
 		if (has_mapping) {
 			StringName target_var = parent_scope_mapping[p.first];
 			if (target_var != StringName()) {
-				ERR_CONTINUE_MSG(p_blackboard->get_parent() == nullptr, vformat("BlackboardPlan: Cannot link variable %s to parent scope because the parent scope is not set.", LimboUtility::get_singleton()->decorate_var(p.first)));
+				ERR_CONTINUE_MSG(p_blackboard->get_parent().is_null(), vformat("BlackboardPlan: Cannot link variable %s to parent scope because the parent scope is not set.", LimboUtility::get_singleton()->decorate_var(p.first)));
 				p_blackboard->link_var(p.first, p_blackboard->get_parent(), target_var);
 			}
 		} else if (is_bound) {
diff --git a/bt/behavior_tree.cpp b/bt/behavior_tree.cpp
index 64d5f4a..afd0feb 100644
--- a/bt/behavior_tree.cpp
+++ b/bt/behavior_tree.cpp
@@ -78,10 +78,10 @@ void BehaviorTree::copy_other(const Ref<BehaviorTree> &p_other) {
 }
 
 Ref<BTInstance> BehaviorTree::instantiate(Node *p_agent, const Ref<Blackboard> &p_blackboard, Node *p_instance_owner, Node *p_custom_scene_root) const {
-	ERR_FAIL_COND_V_MSG(root_task == nullptr, nullptr, "BehaviorTree: Instantiation failed - BT has no valid root task.");
+	ERR_FAIL_COND_V_MSG(root_task.is_null(), nullptr, "BehaviorTree: Instantiation failed - BT has no valid root task.");
 	ERR_FAIL_NULL_V_MSG(p_agent, nullptr, "BehaviorTree: Instantiation failed - agent can't be null.");
 	ERR_FAIL_NULL_V_MSG(p_instance_owner, nullptr, "BehaviorTree: Instantiation failed -- instance owner can't be null.");
-	ERR_FAIL_NULL_V_MSG(p_blackboard, nullptr, "BehaviorTree: Instantiation failed - blackboard can't be null.");
+	ERR_FAIL_COND_V_MSG(p_blackboard.is_null(), nullptr, "BehaviorTree: Instantiation failed - blackboard can't be null.");
 	Node *scene_root = p_custom_scene_root ? p_custom_scene_root : p_instance_owner->get_owner();
 	ERR_FAIL_NULL_V_MSG(scene_root, nullptr, "BehaviorTree: Instantiation failed - unable to establish scene root. This is likely due to the instance owner not being owned by a scene node and custom_scene_root being null.");
 	Ref<BTTask> root_copy = root_task->clone();
diff --git a/bt/bt_instance.cpp b/bt/bt_instance.cpp
index dd0df10..961d3bc 100644
--- a/bt/bt_instance.cpp
+++ b/bt/bt_instance.cpp
@@ -25,7 +25,7 @@
 #endif
 
 Ref<BTInstance> BTInstance::create(Ref<BTTask> p_root_task, String p_source_bt_path, Node *p_owner_node) {
-	ERR_FAIL_NULL_V(p_root_task, nullptr);
+	ERR_FAIL_COND_V(p_root_task.is_null(), nullptr);
 	ERR_FAIL_NULL_V(p_owner_node, nullptr);
 	Ref<BTInstance> inst;
 	inst.instantiate();
@@ -103,7 +103,7 @@ double BTInstance::_get_mean_update_time_msec_and_reset() {
 
 void BTInstance::_add_custom_monitor() {
 	ERR_FAIL_NULL(get_owner_node());
-	ERR_FAIL_NULL(root_task);
+	ERR_FAIL_COND(root_task.is_null());
 	ERR_FAIL_NULL(root_task->get_agent());
 
 	if (monitor_id == StringName()) {
diff --git a/bt/bt_state.cpp b/bt/bt_state.cpp
index 5449943..835d382 100644
--- a/bt/bt_state.cpp
+++ b/bt/bt_state.cpp
@@ -98,7 +98,7 @@ void BTState::_update(double p_delta) {
 		// Bail out if a transition happened in the meantime.
 		return;
 	}
-	ERR_FAIL_NULL(bt_instance);
+	ERR_FAIL_COND(bt_instance.is_null());
 	BT::Status status = bt_instance->update(p_delta);
 	if (status == BTTask::SUCCESS) {
 		get_root()->dispatch(success_event, Variant());
diff --git a/bt/tasks/bt_comment.cpp b/bt/tasks/bt_comment.cpp
index b5689da..d2475b6 100644
--- a/bt/tasks/bt_comment.cpp
+++ b/bt/tasks/bt_comment.cpp
@@ -30,7 +30,7 @@ PackedStringArray BTComment::get_configuration_warnings() {
 	if (get_child_count_excluding_comments() > 0) {
 		warnings.append("Can only have other comment tasks as children.");
 	}
-	if (get_parent() == nullptr) {
+	if (get_parent().is_null()) {
 		warnings.append("Can't be the root task.");
 	}
 	return warnings;
diff --git a/bt/tasks/bt_task.cpp b/bt/tasks/bt_task.cpp
index 11ae322..315344e 100644
--- a/bt/tasks/bt_task.cpp
+++ b/bt/tasks/bt_task.cpp
@@ -163,7 +163,7 @@ void BTTask::set_custom_name(const String &p_name) {
 
 void BTTask::initialize(Node *p_agent, const Ref<Blackboard> &p_blackboard, Node *p_scene_root) {
 	ERR_FAIL_NULL(p_agent);
-	ERR_FAIL_NULL(p_blackboard);
+	ERR_FAIL_COND(p_blackboard.is_null());
 	ERR_FAIL_NULL(p_scene_root);
 	data.agent = p_agent;
 	data.blackboard = p_blackboard;
diff --git a/bt/tasks/decorators/bt_cooldown.cpp b/bt/tasks/decorators/bt_cooldown.cpp
index c16199f..1997bce 100644
--- a/bt/tasks/decorators/bt_cooldown.cpp
+++ b/bt/tasks/decorators/bt_cooldown.cpp
@@ -80,7 +80,7 @@ void BTCooldown::_chill() {
 		timer->set_time_left(duration);
 	} else {
 		timer = SCENE_TREE()->create_timer(duration, process_pause);
-		ERR_FAIL_NULL(timer);
+		ERR_FAIL_COND(timer.is_null());
 		timer->connect(LW_NAME(timeout), callable_mp(this, &BTCooldown::_on_timeout), CONNECT_ONE_SHOT);
 	}
 }
diff --git a/bt/tasks/decorators/bt_new_scope.cpp b/bt/tasks/decorators/bt_new_scope.cpp
index 1c6dd8a..a9232c9 100644
--- a/bt/tasks/decorators/bt_new_scope.cpp
+++ b/bt/tasks/decorators/bt_new_scope.cpp
@@ -32,16 +32,16 @@ void BTNewScope::set_blackboard_plan(const Ref<BlackboardPlan> &p_plan) {
 
 #ifdef TOOLS_ENABLED
 void BTNewScope::_set_parent_scope_plan_from_bt() {
-	ERR_FAIL_NULL(get_blackboard_plan());
+	ERR_FAIL_COND(get_blackboard_plan().is_null());
 	Ref<BehaviorTree> bt = get_root()->editor_get_behavior_tree();
-	ERR_FAIL_NULL(bt);
+	ERR_FAIL_COND(bt.is_null());
 	get_blackboard_plan()->set_parent_scope_plan_provider(Callable(bt.ptr(), "get_blackboard_plan"));
 }
 #endif // TOOLS_ENABLED
 
 void BTNewScope::initialize(Node *p_agent, const Ref<Blackboard> &p_blackboard, Node *p_scene_root) {
 	ERR_FAIL_COND(p_agent == nullptr);
-	ERR_FAIL_COND(p_blackboard == nullptr);
+	ERR_FAIL_COND(p_blackboard.is_null());
 
 	Ref<Blackboard> bb;
 	if (blackboard_plan.is_valid()) {
diff --git a/editor/blackboard_plan_editor.cpp b/editor/blackboard_plan_editor.cpp
index b9dd910..75c1bfc 100644
--- a/editor/blackboard_plan_editor.cpp
+++ b/editor/blackboard_plan_editor.cpp
@@ -46,7 +46,7 @@ LineEdit *BlackboardPlanEditor::_get_name_edit(int p_row_index) const {
 }
 
 void BlackboardPlanEditor::_add_var() {
-	ERR_FAIL_NULL(plan);
+	ERR_FAIL_COND(plan.is_null());
 
 	int suffix = 1;
 	StringName var_name = default_var_name == StringName() ? "var" : default_var_name;
@@ -65,14 +65,14 @@ void BlackboardPlanEditor::_add_var() {
 }
 
 void BlackboardPlanEditor::_trash_var(int p_index) {
-	ERR_FAIL_NULL(plan);
+	ERR_FAIL_COND(plan.is_null());
 	StringName var_name = plan->get_var_by_index(p_index).first;
 	plan->remove_var(var_name);
 	_refresh();
 }
 
 void BlackboardPlanEditor::_rename_var(const StringName &p_new_name, int p_index) {
-	ERR_FAIL_NULL(plan);
+	ERR_FAIL_COND(plan.is_null());
 
 	LineEdit *name_edit = _get_name_edit(p_index);
 	ERR_FAIL_NULL(name_edit);
@@ -96,7 +96,7 @@ void BlackboardPlanEditor::_rename_var(const StringName &p_new_name, int p_index
 }
 
 void BlackboardPlanEditor::_change_var_type(Variant::Type p_new_type, int p_index) {
-	ERR_FAIL_NULL(plan);
+	ERR_FAIL_COND(plan.is_null());
 
 	BBVariable var = plan->get_var_by_index(p_index).second;
 	if (var.get_type() == p_new_type) {
@@ -115,14 +115,14 @@ void BlackboardPlanEditor::_change_var_type(Variant::Type p_new_type, int p_inde
 }
 
 void BlackboardPlanEditor::_change_var_hint(PropertyHint p_new_hint, int p_index) {
-	ERR_FAIL_NULL(plan);
+	ERR_FAIL_COND(plan.is_null());
 	plan->get_var_by_index(p_index).second.set_hint(p_new_hint);
 	plan->notify_property_list_changed();
 	_refresh();
 }
 
 void BlackboardPlanEditor::_change_var_hint_string(const String &p_new_hint_string, int p_index) {
-	ERR_FAIL_NULL(plan);
+	ERR_FAIL_COND(plan.is_null());
 	plan->get_var_by_index(p_index).second.set_hint_string(p_new_hint_string);
 	plan->notify_property_list_changed();
 }
@@ -472,14 +472,14 @@ BlackboardPlanEditor::BlackboardPlanEditor() {
 // ***** EditorInspectorPluginBBPlan *****
 
 void EditorInspectorPluginBBPlan::_edit_plan(const Ref<BlackboardPlan> &p_plan) {
-	ERR_FAIL_NULL(p_plan);
+	ERR_FAIL_COND(p_plan.is_null());
 	plan_editor->edit_plan(p_plan);
 	plan_editor->popup_centered();
 }
 
 void EditorInspectorPluginBBPlan::_open_base_plan(const Ref<BlackboardPlan> &p_plan) {
-	ERR_FAIL_NULL(p_plan);
-	ERR_FAIL_NULL(p_plan->get_base_plan());
+	ERR_FAIL_COND(p_plan.is_null());
+	ERR_FAIL_COND(p_plan->get_base_plan().is_null());
 	EditorInterface::get_singleton()->call_deferred("edit_resource", p_plan->get_base_plan());
 }
 
@@ -501,7 +501,7 @@ void EditorInspectorPluginBBPlan::parse_begin(Object *p_object) {
 void EditorInspectorPluginBBPlan::_parse_begin(Object *p_object) {
 #endif
 	Ref<BlackboardPlan> plan = Object::cast_to<BlackboardPlan>(p_object);
-	ERR_FAIL_NULL(plan);
+	ERR_FAIL_COND(plan.is_null());
 
 	PanelContainer *panel = memnew(PanelContainer);
 	ADD_STYLEBOX_OVERRIDE(panel, LW_NAME(panel), toolbar_style);
diff --git a/editor/editor_property_variable_name.cpp b/editor/editor_property_variable_name.cpp
index 75cdcbe..7d2adf5 100644
--- a/editor/editor_property_variable_name.cpp
+++ b/editor/editor_property_variable_name.cpp
@@ -36,7 +36,7 @@ int EditorPropertyVariableName::last_caret_column = 0;
 //***** EditorPropertyVariableName
 
 void EditorPropertyVariableName::_show_variables_popup() {
-	ERR_FAIL_NULL(plan);
+	ERR_FAIL_COND(plan.is_null());
 
 	variables_popup->clear();
 	variables_popup->reset_size();
@@ -109,7 +109,7 @@ void EditorPropertyVariableName::_update_status() {
 }
 
 void EditorPropertyVariableName::_status_pressed() {
-	ERR_FAIL_NULL(plan);
+	ERR_FAIL_COND(plan.is_null());
 	if (!plan->has_var(name_edit->get_text())) {
 		BlackboardPlanEditor::get_singleton()->set_defaults(name_edit->get_text(),
 				expected_type == Variant::NIL ? Variant::FLOAT : expected_type,
@@ -120,14 +120,14 @@ void EditorPropertyVariableName::_status_pressed() {
 }
 
 void EditorPropertyVariableName::_status_mouse_entered() {
-	ERR_FAIL_NULL(plan);
+	ERR_FAIL_COND(plan.is_null());
 	if (!plan->has_var(name_edit->get_text())) {
 		status_btn->set_button_icon(theme_cache.var_add_icon);
 	}
 }
 
 void EditorPropertyVariableName::_status_mouse_exited() {
-	ERR_FAIL_NULL(plan);
+	ERR_FAIL_COND(plan.is_null());
 	_update_status();
 }
 
@@ -262,7 +262,7 @@ bool EditorInspectorPluginVariableName::_parse_property(Object *p_object, const
 	Variant default_value;
 	if (is_mapping) {
 		plan.reference_ptr(Object::cast_to<BlackboardPlan>(p_object));
-		ERR_FAIL_NULL_V(plan, false);
+		ERR_FAIL_COND_V(plan.is_null(), false);
 		String var_name = p_path.trim_prefix("mapping/");
 		if (plan->has_var(var_name)) {
 			BBVariable variable = plan->get_var(var_name);
@@ -277,7 +277,7 @@ bool EditorInspectorPluginVariableName::_parse_property(Object *p_object, const
 				plan = parent_plan;
 			}
 		}
-		ERR_FAIL_NULL_V(plan, false);
+		ERR_FAIL_COND_V(plan.is_null(), false);
 	} else {
 		plan = editor_plan_provider.call();
 	}
diff --git a/editor/limbo_ai_editor_plugin.cpp b/editor/limbo_ai_editor_plugin.cpp
index 32b6a79..b6c21e8 100644
--- a/editor/limbo_ai_editor_plugin.cpp
+++ b/editor/limbo_ai_editor_plugin.cpp
@@ -200,7 +200,7 @@ void LimboAIEditor::_remove_task(const Ref<BTTask> &p_task) {
 	ERR_FAIL_COND(p_task.is_null());
 	ERR_FAIL_COND(task_tree->get_bt().is_null());
 	EditorUndoRedoManager *undo_redo = _new_undo_redo_action(TTR("Remove BT Task"));
-	if (p_task->get_parent() == nullptr) {
+	if (p_task->get_parent().is_null()) {
 		ERR_FAIL_COND(task_tree->get_bt()->get_root_task() != p_task);
 		undo_redo->add_do_method(task_tree->get_bt().ptr(), LW_NAME(set_root_task), Variant());
 		undo_redo->add_undo_method(task_tree->get_bt().ptr(), LW_NAME(set_root_task), task_tree->get_bt()->get_root_task());
@@ -746,7 +746,7 @@ void LimboAIEditor::_action_selected(int p_id) {
 
 void LimboAIEditor::_on_probability_edited(double p_value) {
 	Ref<BTTask> selected = task_tree->get_selected();
-	ERR_FAIL_COND(selected == nullptr);
+	ERR_FAIL_COND(selected.is_null());
 	Ref<BTProbabilitySelector> probability_selector = selected->get_parent();
 	ERR_FAIL_COND(probability_selector.is_null());
 	if (percent_mode->is_pressed()) {
@@ -1241,7 +1241,7 @@ void LimboAIEditor::_tab_menu_option_selected(int p_id) {
 		} break;
 		case TAB_JUMP_TO_OWNER: {
 			Ref<BehaviorTree> bt = history[idx_history];
-			ERR_FAIL_NULL(bt);
+			ERR_FAIL_COND(bt.is_null());
 			String bt_path = bt->get_path();
 			if (!bt_path.is_empty()) {
 				owner_picker->pick_and_open_owner_of_resource(bt_path);
diff --git a/editor/task_tree.cpp b/editor/task_tree.cpp
index efd57b2..f215539 100644
--- a/editor/task_tree.cpp
+++ b/editor/task_tree.cpp
@@ -192,7 +192,7 @@ void TaskTree::_on_item_collapsed(Object *p_obj) {
 	}
 
 	Ref<BTTask> task = item->get_metadata(0);
-	ERR_FAIL_NULL(task);
+	ERR_FAIL_COND(task.is_null());
 	task->set_display_collapsed(item->is_collapsed());
 }
 
@@ -574,7 +574,7 @@ void TaskTree::_bind_methods() {
 
 // TreeSearch API
 void TaskTree::tree_search_show_and_focus() {
-	ERR_FAIL_NULL(tree_search);
+	ERR_FAIL_COND(tree_search.is_null());
 	tree_search_panel->set_visible(true);
 	tree_search_panel->focus_editor();
 }
@@ -587,7 +587,7 @@ TreeSearch::SearchInfo TaskTree::tree_search_get_search_info() const {
 }
 
 void TaskTree::tree_search_set_search_info(const TreeSearch::SearchInfo &p_search_info) {
-	ERR_FAIL_NULL(tree_search);
+	ERR_FAIL_COND(tree_search.is_null());
 	tree_search_panel->set_search_info(p_search_info);
 }
 
diff --git a/editor/tree_search.cpp b/editor/tree_search.cpp
index e510edd..ff8bb6d 100644
--- a/editor/tree_search.cpp
+++ b/editor/tree_search.cpp
@@ -158,7 +158,7 @@ void TreeSearch::_draw_highlight_item(TreeItem *p_tree_item, const Rect2 p_rect,
 		if (font.is_null()) {
 			font = p_tree_item->get_tree()->get_theme_font(LW_NAME(font));
 		}
-		ERR_FAIL_NULL(font);
+		ERR_FAIL_COND(font.is_null());
 		float font_size = p_tree_item->get_custom_font_size(0);
 		if (font_size == -1) {
 			font_size = p_tree_item->get_tree()->get_theme_font_size(LW_NAME(font));
@@ -176,7 +176,7 @@ void TreeSearch::_draw_highlight_item(TreeItem *p_tree_item, const Rect2 p_rect,
 
 		// Stylebox
 		Ref<StyleBox> stylebox = p_tree_item->get_tree()->get_theme_stylebox(LW_NAME(Focus));
-		ERR_FAIL_NULL(stylebox);
+		ERR_FAIL_COND(stylebox.is_null());
 
 		// Extract separation
 		float h_sep = p_tree_item->get_tree()->get_theme_constant(LW_NAME(h_separation));
diff --git a/tests/test_task.h b/tests/test_task.h
index 5e79ae0..efa3350 100644
--- a/tests/test_task.h
+++ b/tests/test_task.h
@@ -78,7 +78,7 @@ TEST_CASE("[Modules][LimboAI] BTTask") {
 		SUBCASE("Test next_sibling()") {
 			CHECK(child1->next_sibling() == child2);
 			CHECK(child2->next_sibling() == child3);
-			CHECK(child3->next_sibling() == nullptr);
+			CHECK(child3->next_sibling().is_null());
 		}
 		SUBCASE("Test remove_child()") {
 			task->remove_child(child2);
@@ -153,7 +153,7 @@ TEST_CASE("[Modules][LimboAI] BTTask") {
 			CHECK(child3->get_root() == task);
 		}
 		SUBCASE("Test get_parent()") {
-			CHECK(task->get_parent() == nullptr);
+			CHECK(task->get_parent().is_null());
 			CHECK(child1->get_parent() == task);
 			CHECK(child2->get_parent() == task);
 			CHECK(child2->get_parent() == task);