control point can't see MinimServer

[Terry]

Hi
I have recently (with Simon's help) updated minim server to 0.8.5.2 update 123.I now have a problem where the Naim App running on iPad Air does not find minim server.

System details.
- BT home hub 4.
- Apple iMac (OS 10.13.6 (17G65), wired connection to router (via Netgear switch GS108).
- Naim NAC 272, wired connection to router via Netgear switch GS108).
- WD "mybooklive" running Twonky, (wired connection to router via Netgear switch GS108).

The system worked well before updating minim server, the only changes have been a re-install of "ffmpeg" as previous version was deleted in error.

I can't see any error messages in the minim server log:-

[i]MinimServer 0.8.5.2 update 123, Copyright © 2012-2018 Simon Nash. All rights reserved.
MinimStreamer 0.7.7, Copyright © 2012-2018 Simon Nash. All rights reserved.
Java™ SE Runtime Environment (build 1.8.0_181-b13)
Java HotSpot™ 64-Bit Server VM (build 25.181-b13, mixed mode)
Java runtime options: -Dfile.encoding=UTF-8
Platform default charset is UTF-8
Language setting is 'eng'
Current time is Fri Aug 17 07:38:47 BST 2018 in time zone Europe/London
starting MinimServer[terrys-iMac.home]
MinimServer[terrys-iMac.home] is running
Startup complete

[/i]

Any help appreciated,

Terry