After the most recent update, dragging a deconstruction planner over an area leaves a permanent red outline the approximate (but not exact) size of the area marked for deconstruction. I did not notice this happening before the update, but I can't be 100% sure. This persisted even with disaster core belts being the only mod installed.

Hi, i forgot to delete debug code, version 1.3.1 with the fix is up.
If you saved game with the red/blue rectangles that mod created, please run command /c rendering.clear("disastercore-belts")

Awesome, thank you for the quick response!