In majority of the cases when you see a white screen, it means that you exhausted the memory limit. But first you should check what exactly is causing the white screen issue.
In your wp-config.php add the following code:
define( 'TC_DEBUG', true);
Once you add this, the blank screen will now have errors. If the memory is the cause of the issue the error will look like this:
Fatal error: Allowed memory size of 33554432 bytes exhausted (tried to allocate 2348617 bytes) in /home4/xxx/public_html/wp-includes/plugin.php on line xxx
To fix this issue, first you have to open your wp-config.php which is located in the root WordPress directory. Then add the following line:
define('WP_MEMORY_LIMIT', '256M');
First you should check in Tickera System (Tickera > General > System) if you have "allow_url_fopen" allowed on your site (Ticket template might need allow_url_fopen to be allowed on your server in order to retrieve images). If it's not allowed you should contact your host company and ask them to allow it.
Second, it's not allowed login and admin access areas to be secured with HTTP Authentication since cUrl cannot access image URL.
If you are getting the following message: "TCPDF ERROR: [Image] Unable to get the size of the image:" it means that your server doesn't allow retrieving an image via an absolute address:
http:/yoursite.com/wp-content/uploads/2015/08/background.jpg
To fix this error change address of Event/Sponsor logo to relative one:
/wp-content/uploads/2015/08/background.jpg