Seems to be working very well with iOS 8.4.1.

FYI: Sorry for the delay with posting build 1753, it should be finally posted later today.

While 1753 hasn't come out from MM yet, apple did release iOS 8.4.1, and if you read the notes, it has a lot of changes to the music app and sync code. I tried this new iOS with two recent DLLs provided to me by Ludek, and my iPhone 4S has flawlessly synced (using auto sync) all 3 times. No errors, and all songs show in the music app just fine. The sync is a bit slow, but I'll take that over failed syncs and missing songs. I am really starting to wonder if this was all caused by an Apple bug, that was finally fixed in iOS 8.4.1. Perhaps MM still needed to tweak their code and DLLs (they'll tell us), but I finally think we're getting close.

There will be another beta later today (4.1.9.1753) that is stabilizing the individual iOS8 issues, let me know how it works, thanks.

@Ludek; As sync started working again for me before I got a chance to try your new DLL, let me know if it help you if I run another debug so you can compare the two states, not working and working?

The dll file did not work for me. Is there anything else in the works? Same issue as with iOS 8.3, except this time nothing shows up on my phone at all. Thanks.

I tried the DLL today and I could sent a few albums (69 songs) to my 4S - looks promising! I don't use the MM sync function, instead I always right-click on a album and click: send to iPhone.

To be sure I have to test it a bit more.

Cheers
Matosh

Just gave it a shot...only 50 songs show up on phone out of a playlist of 100 songs...not sure. But at least it didn't crash. I uploaded the log to our ticket.

I'll give the DLL a try later tonight Ludek. After trying to solve this with you for over 3 months, it will be great to get it done!

FYI
@MyCsPiTTa and @steveg_nh issues have the same symptomps
both have the mentioned values set to zero in MediaLibrary.sqlitedb for some reason.
I also have been able to simulate the issue by manual editing of MediaLibrary.sqlitedb to zero the values.
The fix (http://www.ventismedia.com/mantis/view.php?id=12813) will be included in the next beta build (4.1.9.1753)

Thanks!

EDIT: If you want to test the fix before the beta will be posted, you can download this iPhoneCalc.dll : http://happymonkeying.com/beta/iPhoneCalc.dll
and replace it over your current iPhoneCalc.dll from the build 4.1.9.1752

Ludek, I sent you the log and my DB file as well.

I've also had inconsistency in syncing too.

Hi Ludek,

Yes, that's great to have some idea so fast - though it's pretty much over my head!

Do you still want me to test more files, or is this on target for fixing now?
Because guess what; I tried another sync today of the "test" playlist and the real playlist I was originally after - and it worked. The files were the same as those not working yesterday.

That would be awesome Ludek! You think this might fix the whole mess?

I think I got it, there are some some unexpected values in /iTunes_Control/iTunes/MediaLibrary.sqlitedb database file:
db_info.db_pid = 0
primary_container_pid = 0

These values used to be expected to be non-zero.

I am tracking the issue as http://www.ventismedia.com/mantis/view.php?id=12813 to be fixed to the next beta version, thanks so far!

@MyCsPiTTa
Based on the log I can confirm that it is the same issue as steveg_nh observes, the device never sends 'AssetManifest', it sends immediatelly 'SyncFinished' after our file metadata commit for some reason. Probably something from the file metadata that it doesn't like, but I cannot reproduce and it is hard to guess what it can be.
Could you test whether this happens for any file or whether it can be related to a particular files? It would give us a clue then.

EDIT: I am analyzing also your iTunes folder to see if I can find something, I will let you now...

Thanks.