Same thing with me, all of a sudden my drawing froze and I can't select entities to modify, edit, erase, etc. All my layers are visible and unlocked.
I opened a different drawing and it worked.
I downloaded DoubleCAD two days ago and I'd like to know what is happening, because I can't invest hours on end to see my drawings freeze at random, making me losing all my work so far.
Is this a bug or can it be some problem with my configuration?