Upload error but file still uploading

Hi, when I test the plugin and submiting a file, the file is downloaded, but I have a php error that tell me: Notice: Undefined index: request_time in /home/…/wp-content/plugins/frontend-uploader/frontend-uploader.php on line 343

can you help me please?

http://ww.wp.xz.cn/plugins/frontend-uploader/