managing queue

[Nizzemancer]

I'm a noob so it might be a dumb question buuuuut:

I've gotten a sidequest that tells me to move building projects up and down in the queue using the arrows but they are unclickable, do I need to wait until a later quest-stage or something or is it a bug?

[Jimmian]

You need to have your build queue full. You can't move the 'currently building', but you can swap queued buildings 2 and 3 using the gold arrows.