error 1: Triggered Ability of Phyrexian Dragon Engine Not Activating When Cast with the Diary of Tarrian
Involved Cards:

Phyrexian Dragon Engine
Diary of Tarrian (artifact-land)
Error Description:

When you cast Phyrexian Dragon Engine using the ability of Diary of Tarrian, the Dragon's triggered ability does not activate correctly.

Explanation:

Phyrexian Dragon Engine has a triggered ability that says: "When Phyrexian Dragon Engine enters the battlefield from your graveyard, you may discard your hand and draw three cards."
Diary of Tarrian is an artifact-land that, when tapped, allows you to play creatures from your graveyard.
The Dragon's ability does not activate, failing to meet the necessary conditions, which could be an error in how these cards interact.

Error 2: Playing the Enchantment "Profane the Graveyard" with Mana Produced by Criptex
Involved Cards:

Profane the Graveyard (Tomb Robber)
Criptex (artifact that gathers clues)
Error Description:

You try to play the enchantment Profane the Graveyard using the mana produced by Criptex, but you are unable to do so.

Explanation:

Criptex is an artifact that, when tapped, produces mana of any color.
Profane the Graveyard is an enchantment that should be able to be cast with any combination of mana produced by Criptex.
If you cannot cast Profane the Graveyard using Criptex's mana, there is an error, as Criptex should allow the production of any color mana needed to cast the enchantment.