This is caused by crash of nm-applet and thus not providing secrets:
[nm-vpn-connection.c:882] get_secrets_cb(): Failed to request VPN secrets #2:
(6) No agents 
The bug is filed as bug 741448.

Update for F15 has been submitted, please test:
https://admin.fedoraproject.org/updates/NetworkManager-0.9.1.90-3.git20110927.fc15

I already updated my NetworkManager with:

yum --enablerepo=updates-testing update NetworkManager

and the same error happened again: 


Oct  4 20:21:36 localhost NetworkManager[9431]: <info> Starting VPN service 'vpnc'...
Oct  4 20:21:36 localhost NetworkManager[9431]: <info> VPN service 'vpnc' started (org.freedesktop.NetworkManager.vpnc), PID 9718
Oct  4 20:21:36 localhost NetworkManager[9431]: <info> VPN service 'vpnc' appeared; activating connections
Oct  4 20:21:36 localhost NetworkManager[9431]: <info> VPN plugin state changed: 1
Oct  4 20:21:36 localhost NetworkManager[9431]: <error> [1317770496.559358] [nm-vpn-connection.c:882] get_secrets_cb(): Failed to request VPN secrets #2: (6) No agents were available for this request.
Oct  4 20:21:36 localhost NetworkManager[9431]: <info> Policy set 'System eth0' (eth0) as default for IPv4 routing and DNS.
Oct  4 20:21:41 localhost NetworkManager[9431]: <info> VPN service 'vpnc' disappeared


[root@karranca ~]# NetworkManager --version
0.9.1.90-3.git20110927.fc15

(In reply to comment #2)
> I already updated my NetworkManager with:
> 
> yum --enablerepo=updates-testing update NetworkManager
> 

Did you restarted NetworkManager? And logged in/out or rebooted, so that new nm-applet is run.

> Oct  4 20:21:36 localhost NetworkManager[9431]: <error> [1317770496.559358]
> [nm-vpn-connection.c:882] get_secrets_cb(): Failed to request VPN secrets #2:
> (6) No agents were available for this request.

This indicated that there's no secret agent that could provide secrets.
What configuration do you use? GnomeShell, fallback mode with nm-applet, KDE, ...?
How did you configure your VPN connection - is the password "always ask"?
Would you paste /etc/NetworkManager/system-connections/<your_con_name>.

At this time mi Gnome shell was bricked by some update that I have no idea, I'll post the informations that you asked about.

(In reply to comment #3)
> Did you restarted NetworkManager? And logged in/out or rebooted, so that new
> nm-applet is run.

Of course, I had rebooted after the NM upgrade.

> > Oct  4 20:21:36 localhost NetworkManager[9431]: <error> [1317770496.559358]
> > [nm-vpn-connection.c:882] get_secrets_cb(): Failed to request VPN secrets #2:
> > (6) No agents were available for this request.
> 
> This indicated that there's no secret agent that could provide secrets.
> What configuration do you use? GnomeShell, fallback mode with nm-applet, KDE,
> ...?

GNOME Shell.

> How did you configure your VPN connection - is the password "always ask"?
> Would you paste /etc/NetworkManager/system-connections/<your_con_name>.

Yes, password is set to always ask.

[connection]
id=[redacted]
uuid=dea58b4a-6e2d-41f5-9d35-d111e5b7b985
type=vpn
permissions=user:amit:;
timestamp=1306165994

[vpn]
service-type=org.freedesktop.NetworkManager.openvpn
connection-type=password
password-flags=3
remote=[redacted]
cipher=AES-256-CBC
reneg-seconds=0
port=443
username=[redacted]
ca=[redacted]
tls-remote=[redacted]

[ipv4]
method=auto
never-default=true

After remove and reinstall my gnome shell I realized that the package gnome-shell-extension-mediaplayers have some problem with this patch and I reinstall my gnome-shell and VPN works fine now.

Thanks,
Samuel
samuel

(In reply to comment #1)
> This is caused by crash of nm-applet and thus not providing secrets:
> [nm-vpn-connection.c:882] get_secrets_cb(): Failed to request VPN secrets #2:
> (6) No agents 
> The bug is filed as bug 741448.
> 
> Update for F15 has been submitted, please test:
> https://admin.fedoraproject.org/updates/NetworkManager-0.9.1.90-3.git20110927.fc15

Having the same problem, although it seems to impact not only VPN connections requiring a password (we use RSA 2 factor auth), but also wireless connections requiring a password (also using RSA or any new network that prompts for a pass).  The above test packages seemed to work.

# yum --enablerepo=updates-testing update NetworkManager

From yum.log
Oct 05 17:53:28 Updated: 1:NetworkManager-glib-0.9.1.90-3.git20110927.fc15.x86_64
Oct 05 17:53:34 Updated: 1:NetworkManager-0.9.1.90-3.git20110927.fc15.x86_64
Oct 05 17:53:34 Updated: 1:NetworkManager-gtk-0.9.1.90-3.git20110927.fc15.x86_64
Oct 05 17:53:36 Updated: 1:NetworkManager-gnome-0.9.1.90-3.git20110927.fc15.x86_64

All is well again.  I'm prompted for passwords for both wireless and vpn connections as I was prior to the following packages getting updates this am:

Oct 05 09:55:43 Updated: 1:NetworkManager-glib-0.9.1.90-1.git20110927.fc15.x86_64
Oct 05 09:56:20 Updated: xulrunner-7.0-1.fc15.x86_64
Oct 05 09:56:22 Installed: 1:NetworkManager-gtk-0.9.1.90-1.git20110927.fc15.x86_64
Oct 05 09:56:33 Updated: 1:NetworkManager-0.9.1.90-1.git20110927.fc15.x86_64
Oct 05 09:56:39 Updated: 1:NetworkManager-gnome-0.9.1.90-1.git20110927.fc15.x86_64
Oct 05 09:57:28 Updated: xulrunner-devel-7.0-1.fc15.x86_64
Oct 05 09:57:37 Updated: firefox-7.0-1.fc15.x86_64
Oct 05 09:58:06 Updated: 1:perl-FCGI-0.74-1.fc15.x86_64

Here are the errors I was seeing on trying to connect to wireless:

Oct  5 15:22:55 USER NetworkManager[978]: <info> Activation (wlan0/wireless): access point 'BLAH' has security, but secrets are required.
Oct  5 15:22:55 USER NetworkManager[978]: <info> (wlan0): device state change: config -> need-auth (reason 'none') [50 60 0]
Oct  5 15:22:55 USER NetworkManager[978]: <info> Activation (wlan0) Stage 2 of 5 (Device Configure) complete.
Oct  5 15:22:55 ebrown NetworkManager[978]: <warn> No agents were available for this request.
Oct  5 15:22:55 USER NetworkManager[978]: <info> (wlan0): device state change: need-auth -> failed (reason 'no-secrets') [60 120 7]
Oct  5 15:22:55 USER NetworkManager[978]: <warn> Activation (wlan0) failed for access point (Red Hat)
Oct  5 15:22:55 USER NetworkManager[978]: <info> Marking connection 'BLAH' invalid.
Oct  5 15:22:55 USER NetworkManager[978]: <warn> Activation (wlan0) failed.
Oct  5 15:22:55 USER NetworkManager[978]: <info> (wlan0): device state change: failed -> disconnected (reason 'none') [120 30 0]
Oct  5 15:22:55 USER NetworkManager[978]: <info> (wlan0): deactivating device (reason 'none') [0]

Other logs of nm-applet crashing during the connection attempt:

Oct  5 15:22:44 USER kernel: [ 1974.042637] nm-applet[4237]: segfault at 0 ip 0000003bed20f6ad sp 00007fff564fd440 error 4 in libgobject-2.0.so.0.2800.8[3bed200000+4c000]
Oct  5 15:22:44 USER abrt[4239]: invalid number '/var/spool/abrt'
Oct  5 15:22:44 USER NetworkManager[978]: dbus_g_proxy_cancel_call: assertion `!DBUS_G_PROXY_DESTROYED (proxy)' failed
Oct  5 15:22:44 USER NetworkManager[978]: dbus_g_proxy_call_no_reply: assertion `!DBUS_G_PROXY_DESTROYED (proxy)' failed

Chandra Kannan and I ran into the same problem.  He pointed out if you just restart the applet, it works again.  I gave it a try.

[shaines@shaines-lap ~]$ nm-applet &
[1] 9583
[shaines@shaines-lap ~]$ ** Message: applet now removed from the
notification area
** Message: applet now embedded in the notification area
[shaines@shaines-lap ~]$ 

All works as expected again.  Short term workaround at least.

(In reply to comment #8)
> Chandra Kannan and I ran into the same problem.  He pointed out if you just
> restart the applet, it works again.  I gave it a try.
> 
> [shaines@shaines-lap ~]$ nm-applet &
> [1] 9583
> [shaines@shaines-lap ~]$ ** Message: applet now removed from the
> notification area
> ** Message: applet now embedded in the notification area
> [shaines@shaines-lap ~]$ 
> 
> All works as expected again.  Short term workaround at least.

I was not able to get this to work, as nm-applet would crash with a sig11 at the time, thus me going w/ the testing pkgs.  I did not, however, save any output from the nm-applet crash, nor any trace info (sorry).  That said, so far so good on the testing pkgs.

This message is a notice that Fedora 15 is now at end of life. Fedora 
has stopped maintaining and issuing updates for Fedora 15. It is 
Fedora's policy to close all bug reports from releases that are no 
longer maintained.  At this time, all open bugs with a Fedora 'version'
of '15' have been closed as WONTFIX.

(Please note: Our normal process is to give advanced warning of this 
occurring, but we forgot to do that. A thousand apologies.)

Package Maintainer: If you wish for this bug to remain open because you
plan to fix it in a currently maintained version, feel free to reopen 
this bug and simply change the 'version' to a later Fedora version.

Bug Reporter: Thank you for reporting this issue and we are sorry that 
we were unable to fix it before Fedora 15 reached end of life. If you 
would still like to see this bug fixed and are able to reproduce it 
against a later version of Fedora, you are encouraged to click on 
"Clone This Bug" (top right of this page) and open it against that 
version of Fedora.

Although we aim to fix as many bugs as possible during every release's 
lifetime, sometimes those efforts are overtaken by events.  Often a 
more recent Fedora release includes newer upstream software that fixes 
bugs or makes them obsolete.

The process we are following is described here: 
http://fedoraproject.org/wiki/BugZappers/HouseKeeping

This message is a notice that Fedora 15 is now at end of life. Fedora 
has stopped maintaining and issuing updates for Fedora 15. It is 
Fedora's policy to close all bug reports from releases that are no 
longer maintained.  At this time, all open bugs with a Fedora 'version'
of '15' have been closed as WONTFIX.

(Please note: Our normal process is to give advanced warning of this 
occurring, but we forgot to do that. A thousand apologies.)

Package Maintainer: If you wish for this bug to remain open because you
plan to fix it in a currently maintained version, feel free to reopen 
this bug and simply change the 'version' to a later Fedora version.

Bug Reporter: Thank you for reporting this issue and we are sorry that 
we were unable to fix it before Fedora 15 reached end of life. If you 
would still like to see this bug fixed and are able to reproduce it 
against a later version of Fedora, you are encouraged to click on 
"Clone This Bug" (top right of this page) and open it against that 
version of Fedora.

Although we aim to fix as many bugs as possible during every release's 
lifetime, sometimes those efforts are overtaken by events.  Often a 
more recent Fedora release includes newer upstream software that fixes 
bugs or makes them obsolete.

The process we are following is described here: 
http://fedoraproject.org/wiki/BugZappers/HouseKeeping