krb5kdc + Wrong OS Time + Losing Wifi Password on start up ...

Same here on my iMac,

Immediately before the error I had to replace the batteries on my magic mouse - not convinced that's relevant.

Time has reynced automatically. I'll reboot and see if the problem has cleared.

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Yes - the reboot was ok with no other actions.

iMac10,1 IM101.00CC.B00 1.53f13 Mac OS X 10.6.7 (10J869)

Magic mouse A1296 3vdc

I just upgraded my iMac to 10.6.8 and now I'm having all of these problems listed above. Any solution? Rebooting did not work for me.

It appears that there are many sources of this problem, but here's one relevant to Macbook Pro. My battery ran down to nothing (the cleaning lady accidentally knocked out the magnetic power connector and I didn't notice). The machine shut down. I noticed the problem, plugged it in and got the same symptom.

I allowed krb5kdc to go out and get the time, and all seems fine now.

Ah. If you use the internet to set your date and time, it's a catch-22: The Mac can't access the internet to set the time because it thinks the WiFi password is invalid because it has the wrong date and time. I manually changed the year to 2011, logged on to my network, reenabled automatic time setting, and so far it looks like it's working.

That makes sense. When my iMac didn't connect to the WiFi router I plugged in an Ethernet cable without really pausing for thought.

I've had de same issue a couple of times since i bought my Macbook pro 15" 2.53GHz Intel Core Duo 2009. Every time that has happen I do these couple of things.

(1). Turn of your Macbook (from the Apple logo).

(2). Hold down left 'Shift' while turning on the computer (startup Safe Mode http://support.apple.com/kb/HT1455 ).

(3). Start 'Disk Utility' ('Applications Folder' and then in 'Utilities Folder')

(4). In 'Disk Utility' mark your Hard Drive and hit the 'Check Disk' button ('Repair Disc' if necessary, if not then move on to step 5).

(5). Hit the 'Check Disk Permission' button. After its done checking, Hit the 'Repair Disk Permission' button underneath (wait til it has repaired all).

(6). Shut down computer (from the Apple logo).

(7). Follow these steps to reset the System Management Controller (SMC) ( http://support.apple.com/kb/ht3964 )

Note: Portable computers that have a battery you should not remove on your own include MacBook Pro (Early 2009) and later, all models of MacBook Air, and MacBook (Late 2009).

1. Shut down the computer.
2. Plug in the MagSafe power adapter to a power source, connecting it to the Mac if its not already connected.
3. On the built-in keyboard, press the (left side) Shift-Control-Option keys and the power button at the same time.
4. Release all the keys and the power button at the same time.
5. Press the power button to turn on the computer.
   Note: The LED on the MagSafe power adapter may change states or temporarily turn off when you reset the SMC.

(8). Go to the 'Clock and Date Settings' If the check for automatic time zone is off, turn it on. Same goes with the 'Check Date and Time Automatic'.

(9). Now it should work (You might have to perform the same thing again when it happens next time. For me its usually once every 6 months - 12 months).

SO this is pretty late but I believe I figured this out. That KRB5KDC error was popping up during startuo along with a window about the firewall. This was happening, the clock was set to january 1, 2001, the Mac App Store would not open, and sometimes the wifi turned off. So if you go to System Preferences---> Security & Privacy ---> Firewall ----> Firewall Options ----> and there was one item that was labeled as "block internet connections" if you just change that to "allow internet connections" it fixed all of those problems INSTANTLY. I rebooted the computer just to double check and it still worked.