With every object on a locked layer, properties.set returned before it
checked the linetype, the dimension style and the dimension overrides, so
it accepted bad values there. They're now checked first, reading the
drawing without writing to it; the drawing is taken for writing, and a new
layer made, only when there are objects to change.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>