(I should really make this a template response or something...)
its likely that you are encountering an error. You would want to consult your PHP error log. You can find the location of your PHP error log in your php.ini.
Alternatively you can turn on error display in osTicket. Direction on how to do that can be found here:
Q: How do I turn on error displaying for osTicket?
http://www.tmib.net/osticket-v19x-frequently-asked-questions-faq#2
You would want to post the error that you are getting here so that we can assist you.
I have debug mode on in OSTicket, and checked my PHP error log setting, which is set to display all. No errors whatsoever, or even warnings, in both.