From the VTTS website...
The failure occurred in the two port side engines (1 & 2) on the ground as the aircraft was easing towards full power at the start of her take-off roll. She is now back in her hangar where the technical team will investigate the problem. Our initial thought is that the symptoms are very much like those experienced when something is ingested by an engine so we will be investigating all possible sources. We would like to thank Robin Hood Airport Doncaster Sheffield (RHADS) for their immediate assistance and professionalism yesterday.
We will provide further updates when we know more.