Bug Reports

I didn't see any "official" Bug Report thread, and Xander9009 suggested that I make one pointing out some of the issues that I've found. I'll try to make this as down and dirty as I can, while still trying to keep it somewhat brief. Alright, here goes.
Creatures:
Angels:
Sigarda, Host of Herons - Forced sacrifice prevention ability does not function.
Slivers:
Manaweft Sliver / Gemhide Sliver - Having multiple copies of either or both cards on the battlefield results in multiple printings of activated ability text on cards (even just having two Manaweft Sliver out will add a second instance of the mana tapping ability to each card). Can result in crashing when other units that acquired the ability attack when 2+ copies are in play (somewhat rare at 2 instances, though with 3-4 out a crash will likely result in a few rounds of constant attacking). Can (almost always will) result in crashing when 3-4+ instances of the acquired ability are on a card, for simply viewing the card (such as trying to tap for mana).
Manaweft Sliver (again) - No longer grants mana tapping ability to other Slivers. Can no longer be tapped for mana. The ability will not activate. This has appeared recently, as in within the last two or three days.
Eldrazi:
Eldrazi Spawn (Tokens) - Incorrect art. TOKEN_ELDRAZI_SPAWN_C_0_1_C_S_MM_CW_1 and TOKEN_ELDRAZI_SPAWN_C_0_1_C_S_MM_CW_2 both depict Fire Elemental tokens. TOKEN_ELDRAZI_SPAWN_C_0_1_C_S_MM_CW_3 depicts a Water Elemental horse. While TOKEN_ELDRAZI_SPAWN_C_0_1_C_S_MM_CW_1 can still be sacrificed for mana (I have not tested the other versions), granted effects from greater Eldrazi and Eldrazi Drones do not function (example: Broodwarden will no longer grant +2/+1 to the spawn tokens).
It That Betrays - The perk of gaining control of sacrificed non-token permanents due to the Annihilator ability do not does not activate while attacking, unless there are two or more copies of It That Betrays under your control. Attacking with other units with the Annihilator ability usually still activate, so long as the single It That Betrays on under your control does not attack (about 70-80% of the time).
Elves:
Wren's Run Packmaster - Does not grant Deathtouch to Wolf creature tokens (tested using Turntimber Ranger. However, this may have also been the result of using Xenograft (type "Ally") to make "infinite wolf tokens").
Artifacts:
Hivestone - Adds type "Slith" to all creatures you control (including Slivers) rather than adding type "Sliver" only to non-Sliver units you control. Appeared recently, as in within the last two or three days.
Land:
Cavern of Souls - Does not accurately allow for creature type selection. When played, it gives a partial alphabetical listing (I believe it only goes to "K" or so) that cannot even be navigated. You have to just randomly click letters until it finally clears, and often auto-assigns type "Giant" no matter what you select.
Reflecting Pool - Does not tap for mana. At all. lol
There's likely more I forgot to list. These are just the ones I remembered immediately while typing this, or which I noticed this evening while building and testing new decks.
I'll add more as I either find them, or remember them.
Cheers.
Creatures:
Angels:
Sigarda, Host of Herons - Forced sacrifice prevention ability does not function.
Slivers:
Manaweft Sliver / Gemhide Sliver - Having multiple copies of either or both cards on the battlefield results in multiple printings of activated ability text on cards (even just having two Manaweft Sliver out will add a second instance of the mana tapping ability to each card). Can result in crashing when other units that acquired the ability attack when 2+ copies are in play (somewhat rare at 2 instances, though with 3-4 out a crash will likely result in a few rounds of constant attacking). Can (almost always will) result in crashing when 3-4+ instances of the acquired ability are on a card, for simply viewing the card (such as trying to tap for mana).
Manaweft Sliver (again) - No longer grants mana tapping ability to other Slivers. Can no longer be tapped for mana. The ability will not activate. This has appeared recently, as in within the last two or three days.
Eldrazi:
Eldrazi Spawn (Tokens) - Incorrect art. TOKEN_ELDRAZI_SPAWN_C_0_1_C_S_MM_CW_1 and TOKEN_ELDRAZI_SPAWN_C_0_1_C_S_MM_CW_2 both depict Fire Elemental tokens. TOKEN_ELDRAZI_SPAWN_C_0_1_C_S_MM_CW_3 depicts a Water Elemental horse. While TOKEN_ELDRAZI_SPAWN_C_0_1_C_S_MM_CW_1 can still be sacrificed for mana (I have not tested the other versions), granted effects from greater Eldrazi and Eldrazi Drones do not function (example: Broodwarden will no longer grant +2/+1 to the spawn tokens).
It That Betrays - The perk of gaining control of sacrificed non-token permanents due to the Annihilator ability do not does not activate while attacking, unless there are two or more copies of It That Betrays under your control. Attacking with other units with the Annihilator ability usually still activate, so long as the single It That Betrays on under your control does not attack (about 70-80% of the time).
Elves:
Wren's Run Packmaster - Does not grant Deathtouch to Wolf creature tokens (tested using Turntimber Ranger. However, this may have also been the result of using Xenograft (type "Ally") to make "infinite wolf tokens").
Artifacts:
Hivestone - Adds type "Slith" to all creatures you control (including Slivers) rather than adding type "Sliver" only to non-Sliver units you control. Appeared recently, as in within the last two or three days.
Land:
Cavern of Souls - Does not accurately allow for creature type selection. When played, it gives a partial alphabetical listing (I believe it only goes to "K" or so) that cannot even be navigated. You have to just randomly click letters until it finally clears, and often auto-assigns type "Giant" no matter what you select.
Reflecting Pool - Does not tap for mana. At all. lol
There's likely more I forgot to list. These are just the ones I remembered immediately while typing this, or which I noticed this evening while building and testing new decks.
I'll add more as I either find them, or remember them.
Cheers.