Clio Semi auto won't work in Auto

I ave recently brought an clio 1.2 57 reg. I am having to drive the car with the check gearbox message on the dash. The car starts with the little A appearing but then disappears and won't come back. Also the car rev an lot when not in neutral , when waiting on an stop between 1500-2000 but sometimes drops to 1000. Are these problems connected and is there an fix.



Car has only done 24000 and gearbox has enough fluid in. Error doesn't come up on fault finding system.