turns over but won’t fire

I have freelander 2, 2008
55,000 miles

About a month ago the car stalled and won’t start, a warning message was displayed
I think it said ‘HDI’ which when I looked up said the battery was on its way out so a got a new battery

Everything was ok for about 3 weeks and now while driving the car lost all power and stops, you restart and it’s ok. This happened 3 times over 10 days

A message popped up saying the service was minus 500 miles

Everything was fine and yesterday morning it wouldn’t start, it turns over ok but won’t fire
The display says ‘Reduce power performance’

Please can anyone give me some advice

Thanks in advance, any help appreciated

It is a 2.2 diesel

It needs the codes read really.

Thank you for replying

Can I get this done at a standard garage or do I need to go a LR garage

Standard garage can do it, but a Land Rover specialist should have more specific knowledge of the causes. Take your pick for a plain diagnostic appointment. For a service, the specialists can work out better, but not always.

Thank you for your help