Reload crossbows when out of mana

So, why did you make it so I can't reload if I run out of mana? Also, if I use mana instead of energy shield, why can't I reload my crossbow when I have no mana? I know it might seem redundant, but can you make it so people can even weapon swap, if they're out of mana? Thanks. Make it make sense, please.

Because crossbow skills don't consume mana on use like any other skill, they consume mana on reload so no mana no reload.

I didnt understand the energy shield and weapon swap part...