Hi barnameha,

1. If only got this problem with large file, then please check http://phpfileuploader.com/FAQ.html#16 "php.ini settings" and "How do I handle a large file upload?" sections, and ensure that your php large file upload settings are correct.

2. Please check the php setting "upload_tmp_dir", ensure that you have set value for this setting and your site has the write/read permission  of the folder you set for this setting.

Regards,

Ken