I've eliminated a few things, but still get the, (like RTs with no notation) but still get the fail. I'm increasingly thinking that it's a failure to run AutoHotKey properly.

If I comment out import_sel_mid_trk_btn_click() it doesn't crash.

I've tried several variations on a theme of running AutoHotKey, but I'm very unclear at present which is the culprit.
At line 37 in "Biab track injector GUI.lua" I have enabled the Msg and appended another thus:
Code:
Msg("script_path "..script_path)
Msg([["/bin/sh -c cd ']] .. [[~/.wine/drive_c/Program Files/AutoHotkey'; ./AutoHotkey.exe]]..[[ ']]..script_path..[[ahk/scripts/Select track number.ahk'"]],0) 		-- GLS

Which gives a console output:
Code:
script_path /home/gordon/.config/REAPER/Scripts/
"/bin/sh -c cd '~/.wine/drive_c/Program Files/AutoHotkey'; ./AutoHotkey.exe '/home/gordon/.config/REAPER/Scripts/ahk/scripts/Select track number.ahk'"

which looks sane but may very well not be.



Some earlier things I'd tried that may give clues where I can debug...
I deleted the temp.txt file and ran the track import again.

I have a MsgBox at the line you suggested and also enabled to one right at the start. I don't get either dialog, which implies I'm not even getting to the code in biab_track_info.ahk

temp.txt has not been created.

This is the console output:
Code:
Error: Biab track injector GUI.lua:1334: cannot open file '/var/BiaB_etc/bb/Data/temp.txt' (No such file or directory)

Stack traceback:
	ReaTrak_Core.lua:93: in function </home/gordon/.config/REAPER/Scripts/ReaTrak_Core.lua:84>
		[C]: in function 'io.input'
	Biab track injector GUI.lua:1334: in function 'read_lines'
	Biab track injector GUI.lua:2694: in function 'gen_cur_track_sec_btn_click'
	Biab track injector GUI.lua:2617: in function 'import_sel_trk_btn_click'
	Biab track injector GUI.lua:1545: in function 'import_all_chk_tracks_btn_click'
	Class - Button.lua:138: in method 'onmouseup'
	ReaTrak_Core.lua:887: in field 'Update'
	ReaTrak_Core.lua:440: in field 'Main_Update_Elms'
	ReaTrak_Core.lua:307: in function </home/gordon/.config/REAPER/Scripts/ReaTrak_Core.lua:303>
		[C]: in function 'xpcall'
	ReaTrak_Core.lua:303: in function </home/gordon/.config/REAPER/Scripts/ReaTrak_Core.lua:302>

Lokasenna_GUI:this is the console output
	v2.16.8
Reaper:
	6.71/linux-x86_64
Platform:
	Other



If generate an apparently sensible temp.txt file from BiaB, so that something does exist and then try to import tracks, this is the console output:
Code:
Error: Biab track injector GUI.lua:2485: attempt to perform arithmetic on a string value (global 'ppq_set')

Stack traceback:
	ReaTrak_Core.lua:93: in metamethod '__div'
	Biab track injector GUI.lua:2485: in function 'import_sel_mid_trk_btn_click'
	Biab track injector GUI.lua:1546: in function 'import_all_chk_tracks_btn_click'
	Class - Button.lua:138: in method 'onmouseup'
	ReaTrak_Core.lua:887: in field 'Update'
	ReaTrak_Core.lua:440: in field 'Main_Update_Elms'
	ReaTrak_Core.lua:307: in function </home/gordon/.config/REAPER/Scripts/ReaTrak_Core.lua:303>
		[C]: in function 'xpcall'
	ReaTrak_Core.lua:303: in function </home/gordon/.config/REAPER/Scripts/ReaTrak_Core.lua:302>

Lokasenna_GUI:
	v2.16.8
Reaper:
	6.71/linux-x86_64
Platform:
	Other

The "Attempt to perform arithmetic..." error suggests a further problem where perhaps the code and a field type don't match as they should?

If it's useful, a temp.txt I generated is here: https://www.dropbox.com/s/vkj43q0fs564yai/temp.txt?dl=0

Jazz relative beginner, starting at a much older age than was helpful.
Kawai MP6, Korg M50, Ui24R, Saffire Pro 40.
AVL:MXE Linux; Windows 11; Win8.1: Scarletts
BIAB2022 UltraPAK, Reaper, a bunch of stuff.