s8 gearbox in safe mode

[audis8tui]

Good evening gents. after putting in a replacement engine that came with a gearbox I decided to use the gearbox as the engine was low mileage and in good condition once checked inside. The engine and box are fitted and the engine running lovely but the gearbox has no drive to the wheels at all.
I have checked the fluid while running and going through the gears and its good. While underneath with my wife running through the gears I can hear the mechanism working and the revs change on the engine.
I have noticed that the dashboard gear indicator doesn't highlight which gear is selected and the mileometer is reading SAFE. I have plugged in the Vagcom and it says solenoid lock. Has any body got any ideas? Regards