***Please read.***
Mario AurelioSep 20, 2015 8:02 AM Re: Does iOS 9 require an SSID to be broadcasted in order to join a wireless network? On previous versions of iOS I was able to connect to my home wireless network when hiding the broadcast of my SSID.
Re: Does iOS 9 require an SSID to be broadcasted in order to join a wireless network? On previous versions of iOS I was able to connect to my home wireless network when hiding the broadcast of my SSID.in response to wifiguru
From Erik @ Apple Support:
"After speaking with you, I started messing around a little with my network and router settings to see what I could do connect to a hidden network with my iPhone. I have a Airport Extreme router, and I restored it to factory settings and set up the network all over again as well as changing the WPA2 password from what it was before. After that was complete, I was successful in connecting to the hidden network with all of my devices including my iPhone 5s with iOS 9.
Not sure this work around will work for you, but just a suggestion. In the meantime, I did send out the engineering request regarding this issue and the engineering team confirmed they received the request."
Therefore, if you Reset your router it should address the issue with the SSID Hidden, and I believe it isn't necessary to change the password. Although, there appears to be an additional issue with MAC Filtering enabled.
I was going to try Erik's suggestion, but as luck would have it my router (Cisco/Linksys E4200 V2) stopped working yesterday. Therefore, I went to best buy and bought a Linksys EA 3500. I installed the new router and it did connect with the SSID Hidden.
After finalizing the configuration of the router I realized that if I enable MAC Filtering (which I have always utilized) I encounter the same message "Could not find the network." The moment I disable MAC Filtering, any device running iOS 9 automatically connects to the network. Therefore, it appears devices running iOS 9 cannot connect to a network if MAC Filtering is enabled.
This latest development was forwarded to Erik at Apple and I will post any updates when received.