Hello,

I think it would be good if the option for show "No answer" in the "presentation and navigation" tab would also count for numerical input and multiple numerical input questions. Because this is an issues when these (multiple) numerical input questions are set as mandatory and the respondent don't want to insert a numerical answer.
Is this a bug or does there exist a explanation for it?

Just a inconsistent behavior of LimeSurvey. You can label that a bug or a missing feature.
Moving "No answer" to every question with additional options would be a solution.
bugs.limesurvey.org/view.php?id=7367
Often a mandatory question should not contain a no answer option. Sometimes a slider question should offer a "No answer" option. Sometimes you need "No answer" and "Don't know" as a second option beside e.g. "other". Flexibility is missing here. So you might end up adapting the survey design to the capabilities of the survey tool.

Ok, thank you for the answer. I wrote a feature request