[Not for this project]Result: Attack declaration invalid

[Flexy]

It keeps happening that I am unable to attack ai players. I am not sure what combination of cards is causing it. It doesn't matter how many opponents I have.

I am playing commander. My commander is Odric, Lunarch Marshal. Current cards on my battlefield are Odric, Reya Dawnbringer with helm of the host, 2nd Rehya Dawnbringer, Danitha capashen paragon, Kytheon Hero of arkos, Extra planer lens, Dawn of Hope, Ajani Goldmane, 4 plains path of ancestry, ancient tomb, Mirn, the Moaning well.

Decklist

1 Ajani Goldmane
1 Akroma's Vengeance
1 Akroma, Angel of Wrath
1 Ancient Tomb
1 Angel of Finality
1 Angel of Invention
1 Angel of the Dire Hour
1 Authority of the Consuls
1 Avacyn, Angel of Hope
1 Aven Sunstriker
1 Basilisk Collar
1 Bastion Protector
1 Bruna, the Fading Light
1 Caged Sun
1 Crackdown
1 Danitha Capashen, Paragon
1 Dawn of Hope
1 Elesh Norn, Grand Cenobite
1 Elspeth, Knight-Errant
1 Elspeth, Sun's Champion
1 Emeria Shepherd
1 Emeria, the Sky Ruin
1 Endless Horizons
1 Enlightened Tutor
1 Entreat the Angels
1 Extraplanar Lens
1 Fumigate
1 Gauntlet of Power
1 Gisela, the Broken Blade
1 Grand Abolisher
1 Guilty Conscience
1 Haunted Cloak
1 Helm of the Host
1 Herald of War
1 Herald's Horn
1 Karakas
1 Karoo
1 Knight of the White Orchid
1 Kytheon, Hero of Akros
1 Land Tax
1 Lightning Greaves
1 Magus of the Disk
1 Marshal's Anthem
1 Masterwork of Ingenuity
1 Miren, the Moaning Well
1 Myriad Landscape
1 Nykthos, Shrine to Nyx
1 Oketra's Monument
1 Open the Armory
1 Path of Ancestry
1 Path to Exile
1 Pearl Medallion
22 Plains
1 Quietus Spike
1 Reliquary Tower
1 Resplendent Angel
1 Return to Dust
1 Reya Dawnbringer
1 Secure the Wastes
1 Shattered Angel
1 Shefet Dunes
1 Skullclamp
1 Smothering Tithe
1 Sol Ring
1 Steelshaper's Gift
1 Stonehewer Giant
1 Stuffy Doll
1 Sun Titan
1 Swiftfoot Boots
1 Sword of Feast and Famine
1 Sword of Vengeance
1 Sword of the Animist
1 Swords to Plowshares
1 Teferi's Protection
1 Urza's Incubator
1 Well of Lost Dreams
1 White Sun's Zenith
1 Wrath of God

[Flexy]

I was just able to attack when I untapped Kytheon, Hero of arkos

[Aswan jaguar]

I understand from what you say that you are not playing Manalink but you are playing either Forge or Xmage. Please say which to move this to their forums as this is a bug forum dedicated for Manalink3.0 (Microprose's old game for MTG still being developed).