Short_open_tag - PHP Error 500

[TGates]

You should not enable short_open_tags for many reasons. One being an issue with using xml coding (which Sentora relies heavily on.)

Excerpt from: http://terrychay.com/article/short_open_tag.shtml

Code:

The real reason is simply that it violates valid XML markup to use short tags.
Simply put, let’s say you have an example where your PHP page has to generate a valid XML
file that needs a XML directive.

<?xml version="1.0" ?>

With short_open_tags, this will generate a fatal error in the PHP engine!
The workaround is to do something nasty like:
    
echo '<'.'?xml version="1.0" ?>';

(or some such). As more websites contained XHTML or some weird sort of sacrifice to the Gods of all
things XML (SOAP, XMLRPC, REST-XML), it was sooner convenient to admit defeat and just start coding
in valid XML markup.

It violates valid xml. It was not recommended for use because it isn’t guaranteed to be on everywhere.
Ever since then people have been in the habit of not using short tags just in case they are off.
Soon, it became part of the php.ini-recommended and short tags, like asp_tags and the alternative
syntax for control structures got relegated to the dustbin of history.

It would be better to update the scripts you are using to use normal php tags versus possibly compromising your server turning on short_open_tags.
Usually a simple process of find-and-replace has worked well for me in the past.