Asset.php

<?php

    /**
     * @return resource
     */
    public function getStream()
    {

        if ($this->stream) {
           if(get_resource_type($this->stream) != "stream"){
        		$this->stream = null;
        	}else{
        		$streamMeta = stream_get_meta_data($this->stream);
        		if (!@rewind($this->stream) && $streamMeta['stream_type'] === 'STDIO') {
        			$this->stream = null;
        		}
        	}
        }

        if (!$this->stream && $this->getType() != 'folder') {
        	if (file_exists($this->getFileSystemPath())) {
        		$this->stream = fopen($this->getFileSystemPath(), 'r', false, File::getContext());
        	} else {
        		$this->stream = tmpfile();
        	}
        }

        return $this->stream;
    }