Does it help to remove the brackets, changing from "(C)" to "C" on line 1? (haven't checked kbm convention - faik it might be needed?).

In my simple copy/paste test of your file, I get an error beginning on line 6.

To fix that, I changed to these values:

! First MIDI note number to retune:
1

instead of 0

and

! Last MIDI note number to retune:
128

instead of 127

Hope it's of help - Not sure if that gives the correct result - but the view in the advanced tuning tab looks interesting and I'd enjoy playing with those intervals a while later and maybe will get around to learning more about kbm files after that.

"Invalid keymap size at Line 1."

Here is my KBM file text:

! Hexany3579(C).kbm:
!
! Size of map. The pattern repeats every so many keys:
19
! First MIDI note number to retune:
0
! Last MIDI note number to retune:
127
! Middle note where the first entry of the mapping is mapped to:
60
! Reference note for which frequency is given:
60
! Frequency to tune the above note to (floating point e.g. 440.0):
261.625565
! Scale degree to consider as formal octave (determines difference in pitch
! between adjacent mapping patterns):
19
! Mapping.
! The numbers represent scale degrees mapped to keys. The first entry is for
! the given middle note, the next for subsequent higher keys.
! For an unmapped key, put in an "x". At the end, unmapped keys may be left out.
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18