I was facing the same issue and this works for me
i installed this plug in and straight away my iphone 5s comes up after restart of MM.
http://www.mediamonkey.com/addons/browse/item/device-plugin-for-itunes/

Just wanted to chirp in that you don't really need iTunes at all.
I did not feel like installing beta MM and decided instead to install the iTunes version that was mentioned earlier in the post.
When you grab the itunes64setup.exe file you can extract it using 7zip. I only needed the application support and mobile device packages and MM see's my phone again (6+ MM couldn't see it when I went to 8.1.3).

Just my two cents (I prefer not to install itunes and bonjour and everything else apple forces you to use just to use your device).

+1 for 1733 fixing this issue

The 1733 fix worked for us also.

Thank you very much! :)

Thank you! MM is again recognizing my iPhone 6 and I can sync again. I was dreading having to go back to iTunes <gag>. I truly appreciate everyone's hard work in getting this out so quickly.

In the Beta forum: http://www.mediamonkey.com/forum/viewtopic.php?p=402588#p402588

Where do I get the MM1732 upgrade??

[quote="blahzicle"]Thanks Peke![/quote][quote="willyvds"]Thanks![/quote] and I thank you all for reporting and patience.

Anyway let me share my story, while we were solving this:
I have number of friends that are iPhone/iPod/iPad fans which they will protect with life along with iTunes.
Just before all this started I updated iTunes (love movie trailers), few of friends came by and we listen music while kids were playing in background. My library is mostly in FLAC so no support in iTunes which resulted in connecting iPhone to MMW resulting NO DEVICE DETECTED. I needed to listen an 1h of explanations why iTunes is better than I remembered that Media PC was running 4.1.5.1719. After upgrade to 1733 all was well, but I needed to be calm while that 1h lasted (my wife kept me on short leash) due the no warnings from iTunes and listenning that MM can't even sync to iPhone.

I have installed 1732 and all works well again. Thanks!
Willy

Haha, sorry I was impatient and it fortunately only took one set of installations. Installed the 1732 MM beta, installed the regular 12.1.1.4 iTunes, booted up iTunes first, ejected my iPod, unplugged it for extra precaution, closed iTunes and booted up MM, plugged in my iPod, and at first it didn't show but I just had to check the box for it under tools < options < portable device sync, then ta-da - all is well. Just hope my music syncs well, but at least I know my device is showing again. Thanks Peke!

I just ran into this issue late last night, after I was forced to update my iPod to iOS 8.1.3 to make a game work and then I accidentally updated iTunes to 12.1.1.4 (the amount of regret I feel over these actions is insane), so I'm beyond relieved to have found this thread. But just to clarify recent resolutions, do I need to use the 1732 beta with my current updated iTunes? Or with the 64 bit for older video cards that's in the "breaks synchronization" link? I've uninstalled and reinstalled these programs so many times today that it would be nice to only have to do it once more for a proper fix; I currently have both uninstalled for the sake of doing things from scratch.

Just to let you know http://www.ventismedia.com/mantis/view.php?id=12545 is fixed and 1732+ works with new itunes x64

[quote="MMLouric"]Not sure I want to remove iTunes and reinstall it.[/quote]That's currently the only option. A more permanent solution seems to be in the works from the bug report.

I have the same sync issue with all of our Apple devices:
iPhone 5, iOS 7.1.2
iPhone 4, iOS 7.1.2
iPhone 6, iOS 8.1.3
iTunes 12.1.1.4, win 7 64bits

All devices are recognized by iTunes, the first two used to synchronized without issues with MM. The iPhone 6 is new, was never synchronzsed with MM and is not recognized.

Not sure I want to remove iTunes and reinstall it. That alone may lead to more troubles. Any permanent fix from MM on the way??

I wouldn't be surprised if any Apple updates could break things again.