LED Lighting Driver and Transformer Enquiry

I recently bought a set of 4 LED strip lights which came with a driver unit but the catalogue listing stated that a transformer was also required. I have installed and connected up the LEDs, the driver and the transformer with a 3amp fuse connection. The LEDS won't illuminate. Please would someone advise me if it is usual to need both a driver and a transformer for LED lighting? Having checked all of the connections (which seem fine)I'm not sure what is wrong! Many thanks in advance.

Are the LEDs wired in series?

Thank you for replying so swiftly. The 500mm LED strips can only be connected with the plugs and leads provided - ensuring correct polarity. I think the strips are connected in parallel. There is only one way of connecting these lights to each other and to the driver unit and the instructions state 'Constant Voltage drivers and parallel connections must be used'

The wiring diagram shows the 12v output load from the driver unit with a 240 V mains supply - no mention of a transformer. (Hence my question regarding the Driver and Transformer combination)

Are they the 5050 strips.
They have a small 4 pin plug that when pushed on back to front the leds will not work.
They use a 240/12 volt power supply that plugs into a controller, then the controller output plugs onto the strip.
The tran is usually sold seperate as the size depends on how many strips you are connecting.

I don't think that they are 5050 LEDs.

What I have is a set of Halolite HA-STH050 Single colour LED strips that came with a 16W Constant Voltage LED Driver. The connections are all 2 pin - the LEDs are mounted in the strip which can be cut shorter if required. The transformer is a Halolite HA-SE60 20-60W VA.