request formData to API, gets “Network Error” in axios while uploading image

I am making a POST request to server to upload an image and sending formdata using axios in react-native. i am getting "Network Error". i also try fetch but nothing work.using react native image picker libeary for select image.in postman api working fine

        formData.append('title', Title);
        formData.append('class_id', selectClass._id)
        formData.append('subject_id', checkSelected)
        formData.append('teacher_id', userId)
        formData.append('description', lecture);
        formData.append('type', 'image');

       var arr=[];
       arr.push(imageSource)
       arr.map((file,index)=>{
       formData.append('file',{
       uri:file.path,
       type:file.type,
       name:file.name
       })
       })


       axios({
       method: 'post',
       url: URL + 'admin/assignment/create',
       data: data,
       headers: {
       "content-type": "multipart/form-data",
       'x-auth-token': token,
        },
       })
     .then(function (response) {
    //handle success
    console.log('axios assigment post',response);
      })
   .catch(function (response) {
     //handle error
      console.log('axios assigment post',response);
    });

"react-native": "0.62.1", "react": "16.11.0", "axios": "^0.19.2",

weird solution i have to delete debug folder in android ->app->source->debug

and restart the app again its solve my problem. i think it's cache problem.