How has Pakistan violated the Vienna Convention in Jadhav case?

The International Court of Justice has said Pakistan violated the Vienna Convention on Consular Relations (VCCR) in retired Indian Navy officer Kulbhushan Jadhav's case. Pakistan didn't inform Jadhav of his rights under VCCR's Article 36 and didn't inform India, without delay, of his arrest and detention. Pakistan also violated the pact by denying Jadhav access to consular officers of India.