I have the V2110 controller and a bunch of AP3825's in my network. Periodically I will hear about someone who is having trouble connecting (either a new client, or an existing client that had previously associated).
It started with an iPad where once a month it wouldn't see the AP. But when they'd bring me the iPad it would work when it was connected to the AP in my office. I finally got to troubleshoot it on site but it wouldn't connect. I told it to forget the network and when I attempted to add it back, it would tell me the password was incorrect. But I walk it down to my office and it would accept the password. I discovered the following web site, but I had already enabled that feature to no avail:
Now it seems to be happening to various devices that are connected to various APs. Today a Windows laptop wouldn't associate. I rebooted the AP and then it would accept the password.
We're running 9.21.15.0006. I'm hoping there is a known bug and all we have to do is upgrade.
I haven't upgraded yet because I still have some AP3660s in the field- I don't believe they are compatible with 10. I'm working on removing/replacing these.