We follow the steps on this documentation http://www.myeventon.com/documentation/show-calendar-another-site-via-iframe/
And in the step 4, in firefox is showing a blank page, when it should show the calendar. You have any idea of what could be wrong?
I am getting a server error. So, please contact your host for assistance:
https://mediatemple.net/community/products/dv/204644990/why-am-i-getting-a-500-internal-server-error-message