Invalid argument foreach

[kibm]

When trying to upload a file i get the following error:

Warning (2): Invalid argument supplied for foreach() [APP/Plugin/file_upload/Controller/Component/FileUploadComponent.php, line 341]

The lines are:

function processAllFiles(){ foreach($this->uploadedFiles as $file){ $this->_setCurrentFile($file); $this->Uploader->file = $this->options['fileModel'] ? $file[$this->options['fileVar']] : $file; $this->processFile(); } }

How to i solve this? Thanks.