The same exact problem happened to me twice. The first time was over a week ago. Messages app kept quitting, and shortly after I restarted my iPhone, all of my contacts were lost. It's probably unrelated, but I did inadvertently open the Verizon Backup Assistant app the day before this happened. I immediately closed the app without doing anything to my contacts. I was also using iOS 5.1.1, since it had been working well and I saw no need to upgrade (especially because of google maps, etc). I restored my iPhone using a backup I had fortunately made a few weeks prior, and got back all contacts except for recently added ones.
Just a few days ago, the same thing happened again, this time overnight after restarting my phone when Safari kept quitting. I went to the Genius Bar at my local Apple Store. I reluctantly agreed to do a factory restore/reboot/whatever on the phone. This upgraded me to iOS 6.1.2, and I also agreed to start using iCloud to back up at least my contacts. I manually sync'ed specific apps and music that I wanted, and it's running great. It's actually running very fast, although I decided to only sync about half the apps I had because I hardly used most of them.
Because I did not restore from a previous backup, there was still the problem of getting my contacts back. After hours of trying to figure out how to manually view data in some of the many backup files, I finally decided to try the iBackupBot software (http://www.icopybot.com/itunes-backup-manager.htm). To my surprise, it worked perfectly and made it easy to see all files, data, etc that were on my previous backup. I was able to save my list of over 100 contacts. Because of the format, I manually added the contacts I wanted back into my phone. It took a while, but I was just happy to be able to successfully retrieve this data from the backup files!
I didn't think I'd say this, but so far I like the newest iOS version and don't seem to notice a battery capacity dropoff. I haven't had further contact list problems yet, and if I do, it should be backed up on iCloud now anyway.
In conclusion, I'm sorry to say that the best option is to do a full restore of the phone and upgrade the iOS anyway. Also use iCloud to at least back up your contacts. If you didn't recently backup your phone in iTunes, then you're probably out of luck in terms of getting contacts back. Also, you'll have to come to terms with losing settings, photos, etc when you restore to factory defaults. Fortunately I got over it pretty quickly. Still though, Apple really needs to look further into how and why this happened!
Thanks for the tip kokokylea. Follow up to your suggestion: turn sync contacts on in iCloud but do NOT turn it off. This will reload all the contacts stored in iCloud. ICloud stores any contacts that were on your phone as of the last time you backed up your phone on your computer or to the cloud. I tried your suggestion yesterday & it restored about 1/3 of my contacts. Went to genius bar today and apparently if I had just left it on yesterday, it would have restored everything I had on there since my August back up (last time I backed up to computer)- I had turned it off before it could recover all the available contacts.
So if you have backed up your phone to a computer or to iCloud at some point, you can at least recover whatever contacts you had on the phone at that time. If you've never backed up your phone, you can try to contact your wireless carrier to see if they can recover. That was the backup suggestion apple tech gave me.
Hope this helps those of you still having issues- good luck!
Is there a chance this is caused by the vunerability linked below? This was discovered in 2009 and I have no idea whether this has been successfully implemented as an attack however it describes being able to take over/crash/wipe and Iphone via an SMS.
Same thing happened to me this afternoon. Message app killed, springboard crash, restarted in safe mode and contacts were wiped. Running 5.1. Seems to be a mass occurance of this happening all around the same time. Unfortunately I never backed up via iTunes so I get the shaft. Can anybody shed some light as to what is going on?
I had the same thing happen a few nites ago. I have 4s running ios 5. I thought it might be because my storage was full to bursting and I've used icloud previously but not in 15 weeks or so. Anyway, I copied all my photos and videos and deleted them. I just found this thread and tried the following and BOOM! Contacts back
Switched phone off after deleting images and video.
Went to SETTINGS-ICLOUD
Switched Contacts (which were set as ON to OFF) then back to ON
When I hit off, it asks 'what would you like to do with the previously synched icloud contacts on your iphone?
I hit 'keep on iphone'
Went to contacts and everything is back.
Time to start using the cloud again, although I am clueless how to find the cloud and retrieve and back up photos for example. Im a photographer and like to backup back up back up multiple copies and with this frustration, I simply copy and backup on my husbands PC as the iphone loads as a HD, why this cant be done on apple is beyond frustrating.
Anyways, hope this works for you all too
Same case for me just now!
I am using 4S with IOS 5.0.1.
keep kick out from apps so decided to restart the iphone.
Then find out the contact list is empty.
never use the icloud before and nothing happen after trying to switch ON and OFF in contact/ICLOUD/SETTING.
so frustrated and annoying now....what should we do?
I am pretty sure those contacts is still somewhere in our phone.
To all those saying they "restart" their phone by holding the sleep/wake (lock) button and home button, that may be exacerbating the issue.
A hard restart by pressing both buttons down is equivalent to pulling the power from a desktop PC - it turns off without shutting down properly, and files on the iPhone can become corrupted.
If the phone is freezing, always turn it off by holding down the sleep/wake button and then "Slide to power off".
Only if the phone will not let you slide to power off should you hard restart.
Or: DON'T RESTART BY HOLDING BOTH BUTTONS DOWN.
Hard booting may not be advised, but I don't think it's causing the issue. Some people hard booted, but others (including myself) just turned it off the way you suggest. We all lost of contacts. Since the apps were alrwady crashing, think the damage was already done prior to turning off the phone (or hard booting).
did you sign back in to icloud with your apple id ? and make sure contacts option is "on" , that how i got my contact back . i figured out that i stored my contact on icloud without me knowing until now ...must be one of the bottom i pressed long time ago or by default . am still think icloud is play funny bugger somehow it replacd my old copy of my contact and after i sign back in few hours ....i have all my current contact back on my phone ...correct me if i am wrong .
good luck .