Suggested fix (unconfirmed): Understand that the icons below your health bar are actually health potions, as mana potions are used immediately upon pickup. Cast spells using 'V' on the keyboard or 'Y' on a controller to consume mana.
Suggested fix (unconfirmed): Press the jump and look combination to use the chains. Restart the game or delete your save file to start fresh if you encounter progression locks.
Day One Fixes