Intermittently, when I try to connect to a WiFi network, I get the following error message as a toast message:

Failed to connect to network

The message pops up immediately upon attempting to connect, so clearly it isn't trying and failing. I haven't found any mention of an error in the logs. The affected networks are ones that I've previously connected to with no change in settings.

How can I figure out what the problem is?

I've got a rooted Galaxy Nexus running Android 4.1.1 and the stock ROM. This question is related to another question that I posted earlier, but this one is more about how to find the source of a particular error message, so its focus is different.

Additional Details

Here are some more details based on the comments:

• I've observed this on my home and work networks. One is identified as WPA2 PSK and the other is identified as WPA/WPA2 PSK.

• I haven't powered off the phone as described in the troubleshooting guide mentioned in the comments. However, I have rebooted to no avail (using the reboot command that's available on rooted phones).

• Forgetting the network and re-adding it has no effect. In fact, if I forget the network I can no longer successfully re-add it.

• The wireless password hasn't changed.

• There's no proxy configured when I'm on wireless. However, I run Onavo Extend when I'm on a data connection. Disabling it has no effect.

• I've switched from DHCP to static IP addresses. Doing so reduced the frequency of problems and seems to have eliminated my earlier issue where wifi would be randomly dropped.

• Wifi sleep is set to "Only when plugged in." I don't think it's relevant because my issue is establishing a connection in the first place (such as when I arrive at home or at work), not maintaining one.

Note that despite all these troubleshooting steps,my initial goal is to find an actual error message or log entry that gives useful information about the problem.

Do you have custom recovery installed? I have had this problem twice on a Galaxy S2, and what fixed it for me every time was running a permissions fix from recovery mode.

If that doesn't work, try deleting your WiFi config file. Not sure what it is on the Nexus, but I'm guessing it'll be something along the lines of /data/misc/wifi/wpa_supplicant.conf or /data/misc/wifi/wpa.conf. Obviously you should make backups before deleting anything. Note that you'll lose all your WiFi settings if you do this.

I think this part of your question is key:

I've switched from DHCP to static IP addresses. Doing so reduced the frequency of problems and seems to have eliminated my earlier issue where wifi would be randomly dropped.

IP addressing issues could certainly cause you troubles like this. Static addressing is only treating the symptoms, though, not curing the disease. Assuming the APs you're connecting to haven't had their DHCP settings changed, focus on investigating how your phone is acting as a DHCP client. I found a bug report in which several users report the same trouble you're having (the author actually references one of your previous questions). One of the commenters found log entries related to DHCP; you mentioned in a comment that you didn't find any relevant log entries but did you see any that look like this commenter's?

Apr 1 05:26:12 unknown daemon.info dnsmasq-dhcp[522]: DHCPREQUEST(br0) 192.168.200.225 a0:0b:ba:83:65:32

Apr 1 05:26:12 unknown daemon.info dnsmasq-dhcp[522]: DHCPNAK(br0) 192.168.200.225 a0:0b:ba:83:65:32 wrong address

Additionally, a later commenter found that the DHCP client service dhcpcd was not running on his device. He explains:

I started researching a bit, using good old Linux console and "ps" command. I noticed that:

• every time I could not connect, dhcpcd was not running.
• at least several times, Kingsoft Office process was running when the problem appeared.

So, what I did was:

• uninstalled Kingsoft Office,
• switch to static IP on all networks I use often (home, work, friends, family). I also disabled WiFi power management (read somewhere that it could help).

After these, problem disappeared. It's been gone for 2 weeks now!

He found that the DHCP client service's absence was correlated with one of his apps. Reconfigure your device to use DHCP, try to connect to one of the problem APs, then use Terminal Emulator (or similar) to run the same investigation he did by typing the command ps | grep dhcp. The output should look something like the following:

dhcp 4858 1 924 552 ffffffff 00000000 S /system/bin/dhcpcd

This means that the dhcpcd process is running. If dhcpcd is not running, you'll simply be returned nothing. If that's the case, type ps again to get a list of all current processes. Do you notice any correlations between an app you've installed and the problems you're having? As a temporary work-around, trying starting the service again by typing sudo dhcpcd, then try again to connect.

I managed to work round, if not resolve, the issue at hand.

In short I installed Wifi Ruler - Free, which overrides the stock wifi connection manager.

This allows me to click and connect to any AP that I come across with no issue.

It does loads of other stuff, finally I can prevent my phone from connecting to my neighbours incredibly strong open wifi.

Hope this helps.

Check to see if you have set mobile data limit. I know it's weird on my samsung Google nexus maguro I removed the limit and wifi returned back to normal.

However I had the same issue on Nexus 7 grouper, I tried various apps and tricks on the net. But finally I had to reflash the Cyanogenmod to get wifi working on it.

I gave this answer to a disconnection query earlier but there is some resonance here.

I think I can guess what is happening. When I first started using free hotspots I was connecting with no problem and often they will have a logon screen to insert the locale password. Some places however like hotels seem to give free access for a limited time or for first use without logging in and then later they will expect you to register.

When I have returned to these places a second time I find that the phone finds the network and claims to be connected but every use returns a network error or appears to connect and get cut off. In fact I am getting rerouted to their logon page, only it seems to often only open in background in gingerbread so you don't know it is happening.

After fiddling around you can sometimes get the logon page to show and then register. Often I can only do this by attempting a google search. Google somehow seems to know to route via the logon pages whereas other apps play ignorant."

Try to reboot your phone, you will find it again after rebooting.

I had the same issue. I found it had to to with my Easy Battery Saver app. Messed around with the settings and it immediately connected.