Mystic Retrieval flashback issues

[Aswan jaguar]

Describe the Bug:
1- Mystic Retrieval when played with flashback if it is the only sorcery and have no instant card in your graveyard to target then it disappears from game.
2- Mystic Retrieval when played with flashback doesn't chose targets while on stack but before.
Which card did behave improperly?
Mystic Retrieval

Which update are you using? (date, name)Which type? (duel, gauntlet, sealed deck)
Manalink dev 778ccb5 version - duel

What exactly should be the correct behavior/interaction?
1- Mystic Retrieval when played with flashback and doesn't have a legal target, (Mystic Retrieval itself isn't a legal target as it is on stack when targets are chosen) certainly doesn't disappear from game.
2- Mystic Retrieval when played with flashback chose targets while on stack.

Are any other cards possibly affected by this bug?
Possibly the other cards which target and with abilities played through Rules Engine.