fix

packages/svelte/src/internal/client/reactivity/effects.js

@@ -433,7 +433,11 @@ export function destroy_block_effect_children(signal) {
 export function destroy_effect(effect, remove_dom = true) {
 	var removed = false;
 
-	if ((remove_dom || (effect.f & HEAD_EFFECT) !== 0) && effect.nodes_start !== null) {
+	if (
+		(remove_dom || (effect.f & HEAD_EFFECT) !== 0) &&
+		effect.nodes_start !== null &&
+		effect.nodes_end !== null
+	) {
 		remove_effect_dom(effect.nodes_start, /** @type {TemplateNode} */ (effect.nodes_end));
 		removed = true;
 	}