Heroic Intervention and Star of Deviation
I cast Star of Devastation, mostly to combo with a Brash Taunter, but my opponent cast Heroic Intervention for his creatures. The normal interaction should be that I still do 20 damage to every creature (triggering Brash Taunter and doing 20 damage to my opponent), but instead the spell fizzled and did nothing. I suspect this is related to the destroy target land aspect of the spell. His land was hexproof so Arena saw that the, mostly inconsequencal, aspect of the spell was targeting hexproof so it fizzled the whole spell instead of just that part.
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[Deleted User] commented
Unfortunately it is not inconsequential. If all targets of a spell are illegal when a spell attempts to resolve, it will fail to resolve and none of its effects will happen.