Whichever way you take, you should get a newer Perl version. If that is not yours to do, at least approach the person who updated the Operating System without also updating relevant applications (that META tag you mentioned is about compatibility). Active Perl is at 5.24 meanwhile, the oldest listed on their website is 5.8 - I doubt they still support 5.6…

The next point is, if you want to do this client side: not only will you need to have the "State.xml" file locally on each client in the appropriate place (which you'll have yet to find out), but you need XML::XPath and probably other modules installed on each client.

So my recommendation is like the others' - go for server side. But have Perl updated anyway!