Draftsight Pro 2018 SP1:

I open ANY 2D drawing,

Select a sole entity, like a line, press delete, the rest of the drawing turns into a mess.  It's VERY similar to deleting a reference from a mesh or 3D object, but everything is on LAYER 0 and 2D (Z=0)  Same drawing edits fine in other applications (SWE, Acad, etc..)

It does this in EVERYTHING...