Ionic 4.2, codenamed Helium, has been released with new features and bug fixes. Notable additions include a new error event for the `<ion-img>` component, allowing a default image to load if the specified one fails, and optional tick marks on the `<ion-range>` slider, thanks to contributions from community members Ivan Tham and Seth Lilly. Bug fixes address issues with Activated Route Observables and improve the DateTime picker, such as defaulting to the local timezone and updating the days when a new month is selected. The Ionic team is also focusing on enhancing desktop support in future updates.