fix: 添加条件判断以确保relatedList为数组后再访问sourceType

src/views/financialManage/invoiceManage/components/addOrEditDialogNew.vue

@@ -560,7 +560,7 @@
     computed: {
       ...mapGetters(['user']),
       isAccountstatement() {
-        return this.form?.relatedList?.[0].sourceType == 1;
+        return Array.isArray(this.form?.relatedList) && this.form?.relatedList?.[0]?.sourceType == 1;
       },
       sourceTypeOp() {
         if(this.$route.path.includes('invoiceManage') && !this.isAccountstatement) {