Hi!
On the armory, if you don’t have any raid progression and are not max level (at least I think that’s the cause), the Dungeons & Raids tab throws an “Oops! Something went wrong” page.
Examples:
Not 120, no raids: https://worldofwarcraft.com/en-us/character/us/gurubashi/dudley/pve/raids
120, no raids (works): https://worldofwarcraft.com/en-us/character/us/kilrogg/fail/pve/raids
Thanks!