Like the title says, after update to v19 Mystic vision has red X and is not available…
save your game with your account, delete device/game cache, restart device, try again
Presuming this isn’t specific to V19, what @_John_Doe said may help, or you could check through one of the main threads for this sort of issue to see other possible solutions (this one below originated when it was a known issue, but has several more recent posts of random issues for specific people):
Duplicate iisue. If @_John_Doe’s suggestion doesnt work, please continue discussion on master threadblinked above.