Collectible Card Game Headquarters

Describe the Bug:
Nighthowler is highlighted, but can't be cast when its owner has exactly 1BB in his/her mana pool and/or in untapped lands. When more mana is available, it can be cast as intended.
Double-clicking it when it's in hand correctly auto-taps the available mana sources and adds the mana to pool, but then nothing happens.

Which card did behave improperly ?
Nighthowler

Which update are you using?(date,name)Which type(Duel,Gauntlet,Sealed Deck)
BotG, Duel

What exactly should be the correct behavior/interaction ?
Nighthowler can be cast as soon as its owner can produce 1BB or has 1BB in his/her mana pool.

Are any other cards possibly affected by this bug ?
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Works for me.

You've got well over 1BB available in that save; is it the right one?

Yeah, I played a fetchland, used it, cast Mortivore and then attempted to cast Nighthowler (and then read your messages, gimme some mins to make up my mind.)
Also buried all lands except for 1 Island and 2 black sources via debug after reloading the save and same bug occured.

Is peculiar. Seems to work in that save so long as I don't crack a fetchland, and not afterwards for the rest of the game. But activating a fetchland in a clean save doesn't prevent it.

Well, I just loaded it again, put a Swamp into play via debug, then cast Mortivore and then attempted to cast Nighthowler and it still wouldn't work, so I'm not sure it's about the fetches. There's none in the graveyard in that savegame, so my guess is I hadn't used one before saving. Also tried burying all lands in excess of 1BB again (without cracking a fetch) and same result turned up.
Can confirm it works as intended in a clean game, though.

Duplicate (I think) of this bug.