Getting error when trying to install POS on Localhost : Fatal error: Can't use method return value in write context

I am trying to install opensourcepos from https://github.com/jekkos/opensourcepos

But I am getting this error:

Fatal error: Can't use method retu value in write context in   D:Xampphtdocsopensourceposapplicationhelperslocale_helper.php on line 67
A PHP Error was encountered

Severity: Compile Error

Message: Can't use method retu value in write context

Filename: helpers/locale_helper.php

Line Number: 67

Backtrace:

I followed instructions, this is a brand new install, I'm at a loss...

I'm on WIndows 7, using Localhost with Xampp

The line 67 is question is this one:

if (empty($config->item('thousands_separator')))

When I comment it out, the site loads, but it doesn't work