Saab 340- trouble taking off

[Gentfam]

I have recently purchased the Saab 340 and it looks good, but, though I have followed the instructions to the letter, I can't manage to get it to take off. I accelerate carefully to 60% of full speed and then the emergency warning light comes on saying "configuration error". I have tried to take off anyway to see what happens, but I go up about 10 feet and just come down again! I must have missed something important, but cannot work out what. Any ideas gratefully received.

Brian