When I import a floor plan from AutoCAD to Rhino saved as a DWG block, there is this insane box/triangle thing that shows up in all of my drawings. It is not specific to any layer and there is no way to select the box. When I delete the layer it is on, it pops up on a different layer that it was not on before. I attached a picture of the thing from different views. PLEASE HELP it’s driving me insane!!!
have you tried opening the ‘blockmanager’ and locating the offending geometry from there ?
Can’t tell you much from the image, could it be that your drawing is very far from the origin? you can try selecting everything, type _move select a point in your drawing and type W0 enter, does this fix the problem?
If not, can you share your drawing so we can take a look at it?