Error #2015: Invalid BitmapData on Assets.getBitmapData

I have swf library that I’m loading as:
<library path="assets/lib.swf" preload="true" />
So, when I try to get a bitmap from this swf with Assets.getBitmapData I get Invalid BitmapData error.
It’s an older game and everything was working fine before and not working now.

I have tried NyanCat sample, while getMovieClip works fine, getBitmapData throws the same error.
Looks like problem is only in Flash target. Any idea why that can happen?
OpenFL 8.9.5 and Lime 7.6.3.