In case you or your customers successfully download the ticket but once you open the downloaded PDF file it is blank, there are couple of things you should check in attempt to resolve this. Majority of the below will require you to edit the ticket template that you're using with the ticket type that has issues displaying the content so before checking any of these suggestions, make sure that you're editing correct ticket template (in case that you have multiple ticket templates). After making any change to the ticket template, you will need to save it and then load the ticket that uses this ticket template from within the Attendees & Tickets area by clicking View. It is advisable to leave the ticket open in one browser tab and edit the ticket template in another as it will make it easier for you to quickly preview any changes you've made.
Edit the ticket template and check the values entered there. If top, left and right margins are too high, the content of the ticket may easily get "pushed" out of the boundaries of the ticket in which case the ticket will indeed look blank.
These margins especially play significant role when smaller ticket format is used (such as A6, A7 or some custom ticket template size).
So, to rule out that this is the case, temporarily set all the margin values to zero and try viewing one of the tickets that uses this ticket template.
Break lines for each individual ticket template element makes it possible to create a gap between the elements and to position them vertically. In some cases, it may happen that, for example, the first element on top is the event image which you haven't set when creating the event in which case this element won't display anything but its break line will still affect the elements below it. So, if this is the case, and the value for the bottom element break line of this element is set too high, it can also "push" all the elements below it out of the boundaries of the ticket template. By the same account, if the element below has top element break line set too high, the result will be the same.
To rule out this as a culprit of the issue, try setting these values to default value of 1 (one) and then try viewing the ticket that uses this ticket template.
If you're using ticket template elements such as Event Logo, Sponsor Logo and Custom image/logo, check the sizes of these images. If the size of any of these images is too big, it may affect the layout, again pushing other elements out of the boundaries of the ticket template. To rule this out, you can temporarily remove these elements from the ticket template, save changes and see if that helped. If it has, then you can experiment with the image sizes to make it fit correctly to your ticket template.
In some cases, a format of the image may mess up the layout. So, if you're using any images on your ticket template (background image as well as Event Logo, Sponsor Logo, Custom logo/image elements), check all the image formats and see which format they have. If they are in .jpg format for example, try changing the format of the image to .png and see if that helps. Also, sometimes, image resolution plays a role in displaying images correctly so make sure that the image you're using is no less than 150 ppi.
Although the issues with fonts mainly revolve around not displaying some non-alphabetic characters incorrectly, it may happen in some rare cases that the text is not displayed at all, especially if you're using Custom Ticket Template Fonts add-on. So, to rule this out, change the font used on the ticket template to some of the default ones, save changes and see if that helped displaying anything at all. If the content is displayed after this, then try re-uploading your custom font and make sure that it is in .ttf format and that it supports the characters used by your language (if your language uses some non-alphabetic characters).
Connect to your website via FTP and edit wp-config.php file. Try finding the line that states something like
define( 'WP_MEMORY_LIMIT', '128M' );
(the value 128M might be different)
If there is no line like this in your wp-config.php file, try adding it right above the line that says
/* That’s all, stop editing! Happy publishing. */
If, however, you have this line in your wp-config.php file, try increasing the value and set it to, say, 128M or 256M.
Try deactivating plugins on your website one by one and each time you deactivate one of the plugins, try viewing the ticket. If you discover that it started working after you have deactivate a specific plugin, contact us via firstname.lastname@example.org and let us know which plugin caused the issue and if possible, send us that plugin, so that our developers can check it out and see what can be done on our end to tackle this.
In some rare occasions, themes may affect rendering process of tickets. To rule this out, temporarily change the theme to one of default "twenty" themes and see if that helped. If that did the trick, contact us via email@example.com and let us know which theme caused this issue so our developers can check it out.
If you have checked this but the issue still persists and you don't know how to tackle it yourself, contact us via firstname.lastname@example.org and provide us with as many information as possible about your website and the steps you have tried before contacting us. Our support agents will get back to you quickly and will help you resolving this issue.