Baldur's Gate : The Sword Coast Chronicles : NWN2 Persistent World

Deadly defense mode randomly sets on 5 hours cooldown, and resets only after the rest. During this cooldown there is no way of reactivating this mode, so if you turn CE off - you can't use deadly defense until you rest.

rightclick on your portrait -> special abilities and just use pommelstrike or charge - usually that will do the trick.

I noticed that this happens not only with deadly defense. Sometimes after entering another area all active abilities of my barbarian are setting on 5 hours cooldown and it is pretty annoying.

Advice given by Theodore01 works with most of bugged abilities, but Bear warrior roar is still on cooldown and only rest helps!