I designed some freighters and set some of my unused shipyards to be able to build them. As soon as I did, the "add task" button in the Create Task section greyed out, rendering me unable to build the freighters. Additionally, I can't build my geosurvey ships anymore either, despite having built a couple of them earlier.
Why can't I build my ships? I have enough minerals, and the shipyards are big enough to build the ships.