Visio questions are on topic here. Microsoft Visio is desktop software and not a programming tool, so it fits here (as opposed to Stack Overflow or Web Apps).
Excerpted from the help center, emphasis mine:
Super User is for computer enthusiasts and power users. If you have a question about …
- computer hardware,
- computer software, or
- personal and home computer networking
… then you’re in the right place to ask your question!
As noted in the comments here, there might not be very many Visio experts on the site, so it could take a while for questions about it to get answered. You can make your questions even better - and therefore a little more likely to get answered - by including screenshots and specific steps (starting from as simple a base as possible) to reproduce problems, as appropriate