You may have encountered an issue where all of a sudden a "raw" shortcode is displayed in place where, for example, event tickets should be displayed. This most likely happened immediately upon updating of Tickera or some of its add-ons that have their own shortcodes. When plugin or add-on updates, it enters a "maintenance mode" during the update and should automatically re-activate itself upon completing the update but sometimes, it gets stuck. So, although in the Plugins area of your website it seems like it is activated, it is actually not and this is why shortcodes are not loading the content as they should.
The solution for this is quite simple; just deactivate and activate the plugin and you're good to go.
To avoid leaving your website with the non-functional shortcodes for a long time and therefore confusing your customers, each time when you update Tickera or some of its add-ons, run through some of the pages or posts that contain Tickera shortcodes and make sure its working. You can even create some private page (not visible to other visitors) where you can place several shortcodes and use that page as some sort of test page.
Note: This issue occurs pretty rarely and does not imply that something is necessarily wrong with Tickera or some of its add-ons. You will most likely never encounter this but if you do, apply a solution mentioned above. If, however, that doesn't help, please contact our support team immediately so they could check what might went wrong.