In a Ruby script I am running, I use the fill_region function to add tiling. I have now encountered a problematic file that generates the following error in KLayout v0.25.3:
Internal error: ../../../src/db/db/dbPolygonGenerators.cc:303 m_open.emtpy () was not true in Cell:fill_region

The fill_region command runs sucessfully in v0.24.8

Required files for reproducing the issue:
Files.zip

Includes the export script, the fill cell, and the problematic cell.

Regards