undefined offset in laravel

I am trying to upload file. Here is my database

id
module_id
name
file
category
ext
size

Here is model:

<?php namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class ModuleMaterials extends Model {

    public $timestamps = false;

    protected $table = 'module_materials';

    protected $fillable = ['module_id', 'file', 'category', 'name', 'ext', 'size'];

    /*
    |--------------------------------------------------------------------------
    | SCOPE SECTION
    |--------------------------------------------------------------------------
    */

    public function scopeForModule($query, $id)
    {
        return $query->where('module_id', $id);
    }

here is file upload:

 $name = Input::get('name');
    $ext = Input::get('ext');
    $module_id = Input::get('module_id');
    $category = Input::get('category');

    $file = $name.'.'.$ext; //str_random(12);
    $path = str_replace("\laravel\dev.oasis-portal.my","\dev.oasis-portal.my",base_path()).'\files\'.$module_id.'\'.$file;

    $data = Request::get('file');

    


    //if(File::makeDirectory(public_path().'\'.'TEST', 0777,true))

     

    list($type, $data) = explode(';', $data);
    list(, $data)      = explode(',', $data);

    $data = base64_decode($data);

    if (!is_dir(str_replace("\laravel\dev.oasis-portal.my","\dev.oasis-portal.my",base_path()).'\files\'.$module_id)) {

      File::makeDirectory($path,0777,true);
    }

    //Write to File
    $check = file_put_contents($path, $data);


  

    $fileinformation = array( 'module_id' => $module_id, 'name' => $name, 'file' => $file, 'category' => $category, 
       'ext' => $ext, 'size'=> strlen($data) );

.....

Here is error:

ErrorException in LecturerController.php line 293:
Undefined offset: 1
in LecturerController.php line 293
at HandleExceptions->handleError('8', 'Undefined offset: 1', 'C:\wamp64\www\oasis_portal\laravel\dev.oasis-portal.my\app\Http\Controllers\LecturerController.php', '293', array('name' => 'taskgroup', 'ext' => 'txt', 'module_id' => '46', 'category' => 'Lectures', 'file' => 'taskgroup.txt', 'path' => 'C:\wamp64\www\oasis_portal\dev.oasis-portal.my\files\taskgroup.txt', 'data' => 'data:', 'type' => 'data:')) in LecturerController.php line 293