Experienced similar issue on Windows. Could not exile cards to reduce mana cost, or was somehow else prevented from targeting an Enduring Angel in play. Opponent had a Enduring Angel in play enchanted with Careful Cultivation. I had 5 open mana. Tried to cast March of Otherworldly Light and exile a white card, but was prevented from targeting Enduring Angel. Angel did not have hexproof.
Experienced similar issue on Windows. Could not exile cards to reduce mana cost, or was somehow else prevented from targeting an Enduring Angel in play. Opponent had a Enduring Angel in play enchanted with Careful Cultivation. I had 5 open mana. Tried to cast March of Otherworldly Light and exile a white card, but was prevented from targeting Enduring Angel. Angel did not have hexproof.