There is a problem when I try to transfer various type of files to Samsung Galaxy Note 4 (latest firmware, os ver. 4.4.4).
For now problem occur with .flac and .ogg files, but I'm sure issue isn't limited to this two. Just to let you know, .mp3 and .mkv file transfer works like a charm.
Here is an issue:
1. I do connect phone via USB 2.0 using Media Transfer Protocol to PC.

2. While using MTP, Windows recognize it as Portable device

3. Double click on it brings me to:

4. I open it and navigate to desired folder («Music» at this point)
5. And try to paste any .flac file here
6. Windows prompt me a popup like this:

7.1 If you press «No, just copy» process gonna stack at ~95%:

7.2 If you press «Yes, convert and copy» process will like this for ever:

PC data:
Windows 8.1 Pro x64 (all updates installed), almost clean and stable OS.
Motherboard: Asus P5Q SE Plus
What have I tried?
- Install/reinstall Kies;
- Reinstall phone driver;
- Camera (PTP) mode;
- USB debugging mode;
- Different USB ports;
- Different .flac files;
- Restarts and reconnects;
- Delete device at Device Manager;
The only way I was able to transfer was method of renaming extension to .mp3 -> transfer -> renaming back to .flac. But this way take a lot of time, laggy a bit and doesn't looks right.
I would be happy to be able transfer files to internal memory without proprietary software (like Kies, WiFi Transfer) and without external services (like DropBox etc.).
Samsung's support was unable to help me, "cause it's a million ways why problem may occur" and it's "hard to say" why do I've it.
Please help me and share your ideas about how this issue can be fixed.
Thank you.
