The London Metal Exchange's attempts to restart nickel trading went awry again — a week after an unheard of short squeeze led the exchange to cancel orders and halt trading.

False starts, IT and system issues thwarted metals traders hoping to resume a sense of normalcy to trading after nickel reached a record high exceeding $100,000 a tonne on 8 March. The LME not only halted trading for eight days, but took the extreme step of cancelling trades, infuriating traders including hedge fund boss Clifford Asness.