Hi @h4m1dreza
This isn't a problem with your version of WordPress, but rather than your version of PHP on the server is outdated.
PHP 5.3 hasn't been supported for security updates since August 2014, and ultimately I've decided not to continue to support it (Despite WordPress itself supporting it).
Please contact your web host and ask to be switched to PHP 5.4 or greater (5.6 would be preferable, but the higher/newer the better).