[OJS 3.0.2] Unable to upload discussion file

that error log is PHP message: PHP Warning: Invalid argument supplied for foreach() in lib/pkp/controllers/wizard/fileUpload/form/PKPSubmissionFilesUploadBaseForm.inc.php on line 209" while reading response header from upstream

i using OJS 3.0.2 and PHP 5.6.4

any solution?

Thanks