fix serialization issue

src/core/common/download.js

@@ -32,6 +32,7 @@ export {
 };
 
 async function downloadPage(pageData, options) {
+	debugger;
 	if (options.includeBOM) {
 		pageData.content = "\ufeff" + pageData.content;
 	}
@@ -70,7 +71,7 @@ async function downloadPage(pageData, options) {
 		warnUnsavedPage: options.warnUnsavedPage,
 		createRootDirectory: options.createRootDirectory,
 		selfExtractingArchive: options.selfExtractingArchive,
-		embeddedImage: Array.from(embeddedImage),
+		embeddedImage: embeddedImage ? Array.from(embeddedImage) : null,
 		preventAppendedData: options.preventAppendedData,
 		extractDataFromPage: options.extractDataFromPage,
 		insertCanonicalLink: options.insertCanonicalLink,