Problems with iTunes, Finder and sharing in 10.9.2

[nightmars]

Hey guys,

After trying to fix some problems for weeks now I ran into a dead end and am desperately looking for some help/advice.
First of all gear:

Mac Mini 2012, 10.9.2
iMac 8.1, 2008, 10.9.2
iPad Air, 7.1
iPhone 5, 7.1
iPhone 5S, 7.1

Problem:
After upgrading all of our devices to 10.9.2 / 7.1 we (instantly) lost some features that we were using (and loving) daily:

1) None of our devices can't sync with iTunes via WiFi anymore. They (sometimes) do show up, but after clicking on them, they disappear.
2) None of our devices can connect to iTunes via the remote app anymore.
3) iTunes (on both computers) won't show my iTunes Server (running on a Synology DS 411slim) anymore --> We can't play any stored music/movies
4) None of our mobile devices can connect to the iTunes library (with the bought movies from iTunes) on the Mac Mini anymore. When opening the videos app on any iDevice it says: No content / you can download videos from the iTunes Store. (We used to stream our videos from the Mini all the time...)
5)On both computers Finder won't show the NAS Server at all. ( I can, however, connect to it using the "connect to server" options with the command: "smb://diskstation" and copy files back and forth...
6) Both computers don't show each other in the Finder at all.--> No file transfer
7) Time Machine won't show the dedicated backup share on the NAS to do backups anymore.

- sharing is turned on
- home sharing enabled (with the same account on all devices)

Thanks for any help/advice/ideas

markus

 

[nightmars]

Well, after keeping trying out weird things it just got really interesting:

When I connect my Mac Mini to the router via cable EVERYTHING immediately starts working as expected... Disconnecting the cable and reconnecting via WiFi - every things stops working as described....

Does anyone have an idea what might be wrong?

markus

 

[davidlv]

Well, after keeping trying out weird things it just got really interesting:
When I connect my Mac Mini to the router via cable EVERYTHING immediately starts working as expected... Disconnecting the cable and reconnecting via WiFi - every things stops working as described....
Does anyone have an idea what might be wrong?
markus

Well, judging from this post, your issue is with WiFi, not iTunes, or sharing per se, so look at this post;
https://forums.macrumors.com/threads/1720092/
about a strange issue a friend had with his MacBook Air, using WiFi.
Deleting 4 preference files (see post No. 16 in that thread) fixed the issue immediately. Worth a try, with no side-effects as far as I could tell.
In that post, you will see a lot of confusing info, but the main thing is that wiFi immediately starting working again as soon as those files were deleted, and replaced automatically by the system on reboot, suggesting that they were corrupted somehow. Could your issue be similar?