ERROR TypeError: Failed to execute 'append' on 'FormData': parameter 2 is not of type 'Blob'. Angular 6
The issue appears to be that the uploaded file was not converted to a Blob.
onImagePicked(event: Event) { const file = (event.target as HTMLInputElement).files[0]; this.form.patchValue({ image: file }); this.form.get('image').updateValueAndValidity(); const reader = new FileReader(); reader.onload = function(e) { this.imagePreview = <string>reader.result; // convert uploaded file to blob const blob = new Blob([new Uint8Array(e.target.result)], {type: file.type }); }; }Source: Convert data file to blob
Perhaps completely unrelated to your question, but in case it may be helpful to someone else, I got the same issue using React when trying to upload multiple files using ant design. My issue was that I was using this:
const formData = new FormData()formData.append( "file", file[0], file[0].name);Which has file[0] as an object
Instead of this:
const formData = new FormData()formData.append( "file", file[0].originFileObj, file[0].originFileObj.name);Which gives me a file.