APs disconnected suddenly from ZD 5000

[ashraf_omar]

Hi
We have ZD 5000 with the S/N:50:A7:33:24:D9:90, and the firmware: 9.12.1.0 build 148. The device is on for about 16 days now, and it has 261 APs connected to it and working with no problem what so ever,until about 4 hours all the APs were disconnected at same time.
I tried to restore the configuration but nothing workout, some of the APs connect again without any change from me.
Is there any thing I can do to save time by configuring the APs manually

[ashraf_omar]

It is the first time that  happened to us, and we couldn't reach to any APs by http or ssh. We had to sent a technician to every AP to reset it and configure it again, and we couldn't find any other way to do it. 

[ismael_kouma]

Surely a connectivity issue