2 episodes of brief central locking failure
The first was about four years ago.
Locked out.Neither remote worked.
Used manual key to open car.
Disconnected battery for half an hour
Reconnected.
Remotes both worked straight away but only close to the car
Over the next few days of use the range gradually extended back to normal.

Then no problems at all for four years.
5 days ago exactly the same problem and exactly the same fix
Fine now..

The first episode was memorable because that was also the night we were awoken by something unusual - a search and rescue helicopter hovering quite low over our house ( we later learnt there was a search for a missing person - there is a wooded area behind our house)

The second episode was also the morning we found that the remote radio- controlled central heating oil tank level device had failed and needed to be re- set [ switched off and then on again)
This has never happened before.

Just strange co-incidences ? or had there have been some electromagnetic disturbance as a cause?

That’s one for Mulder and Scully. 😁. Very strange.

Could easily bt electromagnetic interferrence.

Lots of devices use the same 433MHz band as the car remotes, although not in the USA.

See here
https://www.freel2.com/forum/topic33050.html?highlight=433 FL2 XS SD4 Auto 2010 2012-2017 (21k - 91k miles) (MY2011)
FL2 Metropolis SD4 Auto 2014 2017- (16k - 77k+ miles) (MY2015)
Metro in its 11th Year of (Extended) LR Warranty / Full LR Service History
(Expensive, but Trouble/Worry free - hopefully?)

Is the car used regularly? After a month it goes into deep sleep and the Fobs won't work, the car has to be opened manually. 
Hung like Einstein, smart as a horse.

Link to thread regarding '4 Week Time Out'

The FL2 is designed to gradually shut down all systems until only the Perimeter Alarm is left working.
All other Alarm/Locking functions are disabled.

https://www.freel2.com/forum/topic35264.html?highlight=perimeter FL2 XS SD4 Auto 2010 2012-2017 (21k - 91k miles) (MY2011)
FL2 Metropolis SD4 Auto 2014 2017- (16k - 77k+ miles) (MY2015)
Metro in its 11th Year of (Extended) LR Warranty / Full LR Service History
(Expensive, but Trouble/Worry free - hopefully?)

shiggsy wrote:

Is the car used regularly? After a month it goes into deep sleep and the Fobs won't work, the car has to be opened manually.

Have you (or previous owners) ever had the batteries in the fobs changed? They do loose the capacity to hold charge eventually and the 2007 style fobs don’t have coin cells like the more modern fobs.

vehicle is 2011. fob batteries not changed during my ownership 2016.

central locking working OK - but both fobs working
-previous range restored

Sorry, your vehicle is shown as a 2007. If the problem is sorted now, what was the fix? Just the usual “hard reset” of disconnecting the battery?

the 2007 must relate to my previous one.
Yes, just a battery disconnect for half an hour and then all working when reconnected

- though the range was only a couple of yards at first, improving over the next few days until fully back to normal.

The main battery seems OK too.

Odd.