[EventCalendar] eventcategory does not show up

[Dimitri Janssens]

I was using a name based permalink structure in my website 
www.malagay.es, but my category with the events was showing a 404 
error.
All the events are in the calendar and all the links lead to their 
post, but I could not access the agenda-cultural by clicking the link 
on the navbar.

Is there something I have to change or add in the .htaccess file in 
order to use nice permalinks?