The developers do their best to bring you a stable program. However, with many interacting features and several platforms to support, it’s easy to overlook the occasional issue. Help make Krita a more stable program by reporting bugs through the KDE bug tracker. If you have any issues navigating your way around, there are some instructions from KDE you can follow.
If you’re unsure about reporting a bug in the bug tracker, don’t hesitate, but join us on the forum or on IRC to discuss your problem!