leeneia wrote: Try putting X:1 on the first line of your ABC. I don't know what it means, but it often solves the problem.

I just tried

X: 1
T: Black Joak
R: jig
M: 6/8
L: 1/16
K: Gmaj
D2|:D4G2 G4G2 | A4A2 A3GA3 | B3cB B3AG2|A3BA2 A3GF2|G6 E4D2 | D3EF2 G3 :|
B2|: B4d2 d3ed2| e3fg2 d4B2 | B4d2 d3ed2| e3fg2 d4B2 |c3ca2 B3Bg2 |
|A3BA2 A3BA2 | B3cB2 B3AG2 | A3BA2 A3GF2 | G6 E4D2 | D3EF2 G3 :|

It's got the 'X: 1' but it failed in the mandolintab site. I now use an ABC program on my PC. With Windows I used to use ABC Navigator. Now on Linux I use a program called ABCJ. It works fine for single line music.