Further power problems at the Aragon circuit have forced the cancellation of the second MotoGP and Moto2 Friday practice sessions - just minutes after the go ahead was given for action to resume.
Electricity issues had caused disruption all afternoon, with second 125cc practice delayed by 20 minutes initially.
At the end of that session, another power failure prevented MotoGP's second practice from getting started at all, as the paddock was left without electricity.
Finally, almost two hours after MotoGP practice two was due to commence, power was returned to the circuit and organisers announced that the session would run at 16:20 local time, two hours and 10 minutes late.
But while teams were preparing to get back on track, power at the circuit was lost again. Within minutes it was decided that the remaining MotoGP and Moto2 sessions were being abandoned so that the ongoing issues could be fully resolved.
It is the second time this season that MotoGP has lost a Friday session, following the oil spill that prevented practice two from running at Assen in June.
Saturday morning's practice sessions will be extended to recoup some of the lost track time, with MotoGP practice three running for 75 minutes rather than 45, and starting at 9:35 local time.
Dani Pedrosa had been fastest for Honda in the sole session that did take place today, with Jorge Lorenzo, Casey Stoner, Marco Simoncelli and Andrea Dovizioso next up.