Every time I try to play with my Aria in Shadow Lab, the game tells me I need to purchase the character or one of the Season Two bundles. Though I already own a bundle, I attempted to click the store links and, of course, the store reinforces that I’ve already purchased the character!
Were you using ARIA’s main or Retro costume? I remember somone posting about this issue with a different character at one point where they had made the Shadow at a friends’ house using the Retro costume but couldn’t play with the Shadow at their own house since they did not own or have the Retro costume installed.