A gate that stops and reverses is usually reacting to something it senses as an obstruction. Common causes are a rack that has shifted or collected sand, a wheel or track that has started to bind, a photocell that is partly blocked, or an encoder that has lost its position. Dirty tracks are very common in Abu Dhabi.
A technician will move the gate by hand first to feel for resistance, then test the sensors and the obstruction setting on the board. It is better not to keep pressing the remote, as repeated strain can overheat the motor.