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

[alex_capellan]

The same thing is happening to me with a Vsz-H

[victor_cenac]

Can the APs reach the ZD via ftp?

[ashraf_omar]

How can I do it

[ashraf_omar]

How can I do it