Itunes stucks at "Preparing to sync"

This comes 8 months after the initial question but since I've had this same issue for a while with IOS9 and ITunes v12.x (12.4 now), I thought I would post. I have a solution that tends to work for me though I have no explanation as to what causes the issue. I still get stuck on "Preparing to Update" periodically until I perfom these steps:

1) Make sure phone is disconnected from pc/laptop

2) Perform a reboot of the iphone (hold power and home buttons down for about 10 seconds or so until the screen is black and the white apple logo appears)

3) Reboot the PC/laptop. Either power off/on or do a Restart.

4) Connect phone to pc/laptop. If prompted for "do you trust this computer" select Yes

5) Launch iTunes on the pc

6) Perform the Sync

These set of actions has worked for me several times. I still randomly get stuck on the "Preparing to update" and have to perform these 6 steps for it to work.

Sorry if it doesn't work for everyone, but hopefully this will help someone.

--Dallasdux

I also started seeing this problem this weekend. I have an iPhone 6 and an iPad Mini 2, both running iOS 9.0.2. My computer is running Windows 10 and I have the latest version of iTunes (I even downloaded the most recent version yesterday and had it "repair" my current installation).

iTunes recognizes both of these devices, so it isn't the driver issue that is plaguing many Windows 10 users. After I click on the icon of the device near the upper left corner of iTunes, everything is still set-up the way that I want it to (to sync Calendar and Contacts with Outlook 2016, and Bookmarks with Internet Explorer). After I click on the Sync button, iTunes does a Backup of the iOS device just fine, and then I see the "Preparing to Sync" message at the very top of the iTunes window. Sometimes it does not progress beyond that, but sometimes it will report that it is syncing Calendars, and maybe syncing Contacts, and maybe - if I'm really lucky - syncing Bookmarks.... but it NEVER runs to completion. I have even let it work on it for over 20 minutes, but it just can't get all the way through the Sync operation completely. This same behavior is occurring when I am attempting to Sync either my iPhone or my iPad.

I must add that I can add or remove Music from the iOS device, and the Apps panel correctly shows what is installed on the devices. It's just that for some reason over the past week, I have lost the ability to Sync my iOS devices to Outlook 2016.

I updated iTunes to version 12.3.1 on my Windows 10 64-bit desktop and I updated both my iPhone 6 and my iPad mini 2 to iOS 9.1 yesterday evening.

The very first attempt to Sync my iPhone 6 went very smoothly and very quickly. I was thrilled! Then I tried my iPad.... it was stuck on "Preparing to Sync".

What a Total Letdown.

I am attempting to sync to Outlook 2016, which worked just fine for a few weeks before this problem arose last week. It is Office 365, and I installed the 32-bit version on my Windows 10 64-bit computer.

I tried the Sync over WiFi, and it behaves exactly the same as it does over the USB cable. I have NOT been able to Sync my iPhone again since the iPad was unsuccessful. Also worth noting is that after a failed sync attempt, I close iTunes and then attempt to open Outlook to see if my Calendar and Contaces are still OK, but Outlook will not open (it is stuck on the splash screen saying that it is "Opening Profile"....). If I reboot the computer, I can then open Outlook just fine.

I spent a little more time yesterday evening trying a few more things in hopes that I could find something/anything to get this to work again for me

I tried all of these steps with both my iPhone 6 and my iPad Mini 2.

1. I started iTunes by right-clicking on its icon and choosing to Run as Administrator.

2. Once in iTunes, on the menu bar (Ctrl + B will toggle its visibility), I went to the Help menu and chose to run the Diagnostics. I selected all of them, except the CD/DVD drive test. Everything passes with a green (good) indicator.

3. I went into the Preferences, clicked on the Device tab, and then clicked on the button to Reset Sync History.

4. I went to the left panel of iTunes and clicked on Info. Near the bottom I told iTunes to overwrite the Contacts, Calendar, and Bookmarks on the iPhone.

Nothing. After all of this, iTunes will backup the iOS device, I briefly see a message flash by about Diagnostics being transferred (I don't recall the exact message), and then it will either get stuck on "Preparing to Sync" or "Syncing Contacts". After 15 minutes, or whenever my patience runs out, I can click on the spinning little sync activity indicator and cancel the sync. That indicator then turns into the Eject icon, so I click that to disconnect the iOS device from iTunes.

I give up. I appear to be the only person in the iTunes Universe that has this problem, and I am completely out of ideas to try. I suppose that I will just have to wait for some undetermined amount of time into the future and just hope that some updated version of either Windows 10 64-bit, Microsoft Outlook 2016, iOS, or iTunes will eventually resolve this issue for me.

Although I said that I was giving up, I just can't seem to do that.... I have managed to get my Outlook 2016 Contacts and Calendars, as well as my Internet Explorer Favorites (Bookmarks) onto both my iPhone 6 and my iPad Mini 2, but neither iTunes or the iOS devices feel that the sync completed normally. Here's what I did (this is from memory, so I may not remember the exact names of all of the buttons and menus):

1. Open iTunes 12.3.1

2. Attach my iOS device to my Windows 10 Home 64-bit computer.

3. iTunes recognizes the device, so I click on its icon to enter the sync environment.

4. Go to the Help menu (Ctrl + B toggles its visibility) and choose Run Diagnostics.

5. Unselect the CD/DVD Test, and then run all of the diagnostics. They all report back "green good conditions".

6. Go to the left panel and click on Info.

7. Contacts and Calendars are set to sync with Outlook (which is version 2016 which I obtained from my Office 360 subscription). I also have Bookmarks set to sync with Internet Explorer (because I can't choose Edge). Below that, check the 3 boxes so that the Contacts, Calendars, and Bookmarks will overwrite what is on the device.

8. I go back to the Summary page, and click on Sync at the bottom of the window.

9. iTunes will backup the device, transfer some diagnostics info, and the show me "Preparing to Sync" and then maybe "Syncing Contacts" (if I'm really lucky). I let the spinning progress indicator spin for 15 minutes or so.

10. While the Sync is still running (but stuck), I go back up to the Help menu and choose to once again run the diagnostics (without the CD/DVD tests).

11. The diagnostics will again complete and everything is reported to be in "green good condition".

12. As soon as I close the diagnostic window, the top of the iTunes window changes the message from "Syncing Contacts" to "Waiting for changes to be applied".

13. I let the spinning progress indicator spin for another 15 minutes or so.

14. And yes, once again, hile the Sync is still running (but stuck), I go back up to the Help menu and choose to once again run the diagnostics (without the CD/DVD tests).

15. The diagnostics will again complete and everything is reported to be in "green good condition".

17. Going back into the Info window, the three boxes are no longer checked for overwriting the Calendar, Contacts, and Bookmarks on the device....

18. At this point, I just want this to all end, so I click on the spinning progress indicator and hope that it will change to the Eject icon (it did not for my iPhone 6, but it did for my iPad Mini 2.

19. Since the icon did change for my iPad, I clicked on it and then disconnected the USB cable. Since the icon just kept spinning for my iPhone, I had no other choice but to just disconnect the cable.

20. On the device, going into Settings -> General -> iTunes Wi-Fi Sync, the device does not indicate that it was just sync'ed. Checking the Contacts, Calendars, and Bookmarks clearly indicates that the data was indeed transferred to the iOS device, though.

21. On the device, going into Mail, Contacts, Calendars and under the Contacts section, the My Info field needs to be pointed to my contact info.

Although I do not have a solution yet, I do now see a couple of other forum threads that are reporting this same issue. By observing them, it appears that this is not necessarily a Windows 10 problem, nor is it an Outlook 2016 problem.

iTunes 12.3 stuck at preparing to sync when using USB to sync with iphone 6 ios 9.1

iTunes 12.3.1.23 64-bit Win10 stuck on sync iPhone & iPad

I have the same issue in Windows 7 and Outlook / Office 2013 whether or not Wifi Sync in enabled. This has been occurring over the last 2 months I believe.

Using most recent ITunes and iOS on iPhone 5.