I am unable to load ASCII STL files.
Error recreated here: https://playground.babylonjs.com/#37CYRE#1 (please note, this uses the file system API to load the file, so only works in chrome based browsers).
It works as expected for binary STL files, but fails for ASCII ones. Both exported from blender in linux.
The importer appears to fail to find any meshes, and reports no errors with the file.
example file:
solid Exported from Blender-4.0.2
facet normal 0.000000 0.000000 1.000000
outer loop
vertex 1.000000 1.000000 1.000000
vertex -1.000000 1.000000 1.000000
vertex -1.000000 -1.000000 1.000000
endloop
endfacet
facet normal 0.000000 0.000000 1.000000
outer loop
vertex 1.000000 1.000000 1.000000
vertex -1.000000 -1.000000 1.000000
vertex 1.000000 -1.000000 1.000000
endloop
endfacet
facet normal 0.000000 -1.000000 0.000000
outer loop
vertex 1.000000 -1.000000 -1.000000
vertex 1.000000 -1.000000 1.000000
vertex -1.000000 -1.000000 1.000000
endloop
endfacet
facet normal 0.000000 -1.000000 0.000000
outer loop
vertex 1.000000 -1.000000 -1.000000
vertex -1.000000 -1.000000 1.000000
vertex -1.000000 -1.000000 -1.000000
endloop
endfacet
facet normal -1.000000 0.000000 0.000000
outer loop
vertex -1.000000 -1.000000 -1.000000
vertex -1.000000 -1.000000 1.000000
vertex -1.000000 1.000000 1.000000
endloop
endfacet
facet normal -1.000000 0.000000 0.000000
outer loop
vertex -1.000000 -1.000000 -1.000000
vertex -1.000000 1.000000 1.000000
vertex -1.000000 1.000000 -1.000000
endloop
endfacet
facet normal 0.000000 0.000000 -1.000000
outer loop
vertex -1.000000 1.000000 -1.000000
vertex 1.000000 1.000000 -1.000000
vertex 1.000000 -1.000000 -1.000000
endloop
endfacet
facet normal 0.000000 0.000000 -1.000000
outer loop
vertex -1.000000 1.000000 -1.000000
vertex 1.000000 -1.000000 -1.000000
vertex -1.000000 -1.000000 -1.000000
endloop
endfacet
facet normal 1.000000 0.000000 0.000000
outer loop
vertex 1.000000 1.000000 -1.000000
vertex 1.000000 1.000000 1.000000
vertex 1.000000 -1.000000 1.000000
endloop
endfacet
facet normal 1.000000 0.000000 0.000000
outer loop
vertex 1.000000 1.000000 -1.000000
vertex 1.000000 -1.000000 1.000000
vertex 1.000000 -1.000000 -1.000000
endloop
endfacet
facet normal 0.000000 1.000000 0.000000
outer loop
vertex -1.000000 1.000000 -1.000000
vertex -1.000000 1.000000 1.000000
vertex 1.000000 1.000000 1.000000
endloop
endfacet
facet normal 0.000000 1.000000 0.000000
outer loop
vertex -1.000000 1.000000 -1.000000
vertex 1.000000 1.000000 1.000000
vertex 1.000000 1.000000 -1.000000
endloop
endfacet
endsolid Exported from Blender-4.0.2