DeflateWriter.php
public function finish()
    {
        $this->write('', ZLIB_FINISH);

        $this->file = null;
        $this->deflateContext = null;
    }
public function finish()
    {
        $this->write('', ZLIB_FINISH);

        $this->file = null;
        $this->deflateContext = null;
    }
Make sure all data was written