At the end of the process of all events and updates, those values for the slider and spin box are out of synchronization, so there is a real error if they have to be. For my case the crash is more annoying than this error, considering that it occurs only for some specific cases where it’s not a problem to have slightly different values so it is a very minor bug, but maybe other people needing exact match will have bigger issues…
Replacing the assert by a log could be a first easy step, better having a “polluted” log than a crash.
I see in different places of these ctkRange classes that sometimes the values are forced set for specific cases, so it could be a possibility if we can detect this rounding side effect, but i’m new to ctk/Slicer so i don’t know the impact of it in other cases, these widgets are pretty complex.