If you edit the script then do a search for:
reaper.JS_Dialog_BrowseForFolder
just copy that text then on the script window Ctrl+F Ctrl+V Enter
if you have that function installed the text should be all yellow.
Biab track injector GUI.lua:1685: attempt to call a nil value (field 'JS_Window_Find')
go the line 1685 and check the text "reaper.JS_Window_Find" is yellow that the function is installed via SWS Extensions.
Biab track injector GUI.lua:2487: attempt to perform arithmetic on a nil value (global 'ppqpos')
it should be reading "x:\bb\Data\trackdata.txt" to get the midi info to insert in the reaper track.
there should be text in trackdata.txt like:
Paste into a spreadsheet. List of Events in the track= 147
Status Channel Stamp Bar Beat Tick120 NoteNum Name Vel Duration
NoteOn 3 1080 1 2 0 69 A 5 84 240
NoteOn 3 1320 1 4 0 69 A 5 84 60
NoteOn 3 1380 1 4 60 72 C 6 84 60
NoteOn 3 1440 2 1 0 71 B 5 84 360
.....
.....