UNC limitation with export config?

Support
1

Environment

  • Windows 11
  • Mp3tag 3.33 (64-bit) Jan 22 2026 09:44:14
  • NAS: Synology DS1819 via SMB

Issue
Exporting to a UNC path causes Mp3tag to write a literal "\t" (bytes 5C 74) instead of a TAB (09) when using $char(9).
Exporting to a local path or to a mapped network drive works as expected.

Export configuration (single line)
$filename(,utf-8)Dateiname$char(9)WWW$char(13)$char(10)$loop(%_path%)%_filename_ext%$char(9)%www%$char(13)$char(10)$loopend()

Steps to reproduce

  1. Load MP3 files in Mp3tag (Ctrl+A to select all)
  2. Export using the configuration above, changing only OUTPUTPATH:
    A) Local: C:\Temp\mp3tag_bugreport\mp3_www.tsv -> OK
    B) Mapped: S:__kv\mp3tag_exports\mp3_www.tsv -> OK
    C) UNC: \DS1819\Songs__kv\mp3tag_exports\mp3_www.tsv -> NOT OK
  3. Do NOT open the output file after export
  4. Verify with PowerShell: Format-Hex -Path -Count 120

Expected result

  • TAB byte 09 between columns for all output paths.

Actual result

  • Local path: TAB works (file shows separate columns).
  • Mapped drive: TAB works (file shows separate columns).
  • UNC path: output contains literal backslash+t (5C 74) between columns.

Hex evidence (UNC output)
0000000000000000 ... 44 61 74 65 69 6E 61 6D 65 5C 74 57 57 57 ... (Dateiname\tWWW)
... later: ... 2E 6D 70 33 5C 74 68 74 74 70 73 ... (...mp3\thttps...)

Notes

  • Same NAS share via mapped drive works; only the UNC form fails.
  • Not tested with latest development build yet. (Can test if needed.)
2

Here the hex code of Output on locally mapped NAS Path (which is good!)

Label: Z:__kv\mp3tag_exports\mp3_www_mapped_drive.tsv

      Offset Bytes                                           Ascii
             00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F
      ------ ----------------------------------------------- -----

0000000000000000 EF BB BF 0D 0A 44 61 74 65 69 6E 61 6D 65 09 57 ��Dateiname�W
0000000000000010 57 57 0D 0A 0D 0A 56 61 6E 5F 4D 63 43 6F 79 5F WW����Van_McCoy_
0000000000000020 54 68 65 5F 48 75 73 74 6C 65 28 43 75 73 74 6F The_Hustle(Custo
0000000000000030 6D 5F 42 61 63 6B 69 6E 67 5F 54 72 61 63 6B 29 m_Backing_Track)
0000000000000040 2E 6D 70 33 09 68 74 74 70 73 3A 2F 2F 77 77 77 .mp3�https://www
0000000000000050 2E 6B 61 72 61 6F 6B 65 2D 76 65 72 73 69 6F 6E .karaoke-version
0000000000000060 2E 63 6F 6D 2F 63 75 73 74 6F 6D 62 61 63 6B 69 .com/custombacki
0000000000000070 6E 67 74 72 61 63 6B 2F ngtrack/

3 
Update: Verified with PowerShell Format-Hex:
- UNC path (\\DS1819\...) -> bytes 5C 74 between columns (literal "\t")
- Mapped drive (Z:\...) -> byte 09 between columns (real TAB)
- Local (C:\Temp\...) -> byte 09 between columns (real TAB)
Same export config with $char(9); only output path differs.
4

I just created an export file on my Fritzbox with the sample script - and the tab character appears like expected:
grafik
This is what the export script looks like:
grafik

The export path was like this:
grafik

6

I've moved this to Support now, it's unclear if this issue is still present for the OP.

8

I've just tried to reproduce this too, and it correctly writes a TAB 0x09

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