Disco 2 ACE warning alarm

Hi all, i'm new to this forum and new owner of Discovery II, Estate of 2004, 2.5 Diesel Engine. I have just bought this car direct from U.K end of May this year. I have driven about 980 miles so far and the car came with 93580 miles from the seller. Yesterday I travelled about 230 miles , when i reached 95 miles to get home ACE warning alarm started to ring, then i stopped the car after a while the alarm sound faded while red warning light continue to flash on the dashboard, after 15 minutes i continued driving and arrived home safely. In the morning, i started the engine and drove 5 miles red warning light was not there. This was second time, i remember few days a go i experienced same thing. Please may you assist what should i do now? could be a reason of dirty ACE fluid need to be replaced?

Thanking you in advance.

is the fluid reservoir full

Yes i have checked fluid reservoir is full (at MAX mark) and when engine started the fluid circulates inside the reservoir.

They can red light error for a few reasons none related to fluid loss.

Solenoids too slow.

Wiring to solendoids.

Start with a fluid change using correct oil.

The direct and easy way to fix this is to read the fault code with dediated tester, nanocom is unreliable when it comes to ACE fault codes

Thank you all for your comments. I have not experienced that issue again but i planned to conduct checks of my DISCO soon, will share to you the outcomes. Thank you members, i have learnt a lot through your comments.