This page is updated when we are aware of a widespread bug or issue affecting Cupla. If something is listed here, we're already working on it.
iPhone: the + button can disappear from the calendar at large text sizes. A fix is on the way. In the meantime you can add events from the Home screen (+ in the top right, then Add Event), or reduce your device text size — see How do I adjust the font size?
If you're experiencing a problem that isn't listed here, please see Basic Troubleshooting — Try these steps first, or report a bug to our support team.