fix: possible typeerror on transaction.js
diff --git a/erpnext/public/js/controllers/transaction.js b/erpnext/public/js/controllers/transaction.js
index 4d8f683..18b0f0f 100644
--- a/erpnext/public/js/controllers/transaction.js
+++ b/erpnext/public/js/controllers/transaction.js
@@ -790,7 +790,7 @@
 				if (me.frm.doc.price_list_currency == company_currency) {
 					me.frm.set_value('plc_conversion_rate', 1.0);
 				}
-				if (company_doc.default_letter_head) {
+				if (company_doc && company_doc.default_letter_head) {
 					if(me.frm.fields_dict.letter_head) {
 						me.frm.set_value("letter_head", company_doc.default_letter_head);
 					}