I have an Angular app that I have recently modified to use FormData to store user input data and a file I want to send over the server side. formData.append("photo", this.file); formData.append("obj", JSON.stringify(this.newObj)) this.dataService.addObj(formData) the data service public addObj(formData: any): Promise<any> { return this.http .post(url, formData) .toPromise()} the service returns error 503 when I use the FormData data type but If send just the obj itself it works as expected. This: this.dataService.addObj(obj) works just fine. If I just append the obj (without the file) it still gives me the same error. I am using multer and here is the route the server route: router.post("/", upload.single("photo"), somemiddleware, objCreateFunction); Continue reading...