We are currently experiencing a problem where, on some iPhones and iPads, ibisPaint X closes immediately after launch and cannot be started after updating to ver. 14.1.4.
We apologize for any inconvenience.
Open Settings > General > iPhone Storage (iPad Storage on iPad) > ibisPaint X, confirm that the note below the "Offload App" button says that its documents and data will be kept, and then tap that button. If this note is not there, it is a different button, so please do not tap it.
After that, download the app again from the ibisPaint X icon on the Home Screen (or from the App Store) to work around this problem.