Hello Jan,
I had the same issue with my naimUniti1. I guess it did occur because the update of the firmware did not 100% complete.I accidentally had the device connected to the network via WLAN instead of LAN while updating. The update process did change the WLAN SSID to "naim" instead of the one of my WLAN, so after the installer had done a reboot it could not connect to the network anymore to cleanly finish the installation.
I also tried to reflash the firmware with a LAN connection. But that did not help. The message did show up again.
My solution was: Reset the device to the factory settings. The disadvantage is that you will loose all your settings (including radio/webradio channels, etc.). But after this the device did work fine again (for a week now. But as the "Switch OFF" message did show up several times a day I think it is healed.).
After the factory reset your remote control probably will not work anymore. See my posting here for reconnecting it again to the uniti:
https://forums.naimaudio.com/to...98#29724958802871898
Greetings,
Gert