I installed a free trial version of Draftsight on my company PC, in order to perform a comparison with AutoCad 2D (our current drafting tool). 
After performing the installation, I tried to open an existing 2D dwg drawing but it was displayed slanted and deformed like a 3D view.

I disabled all 3D viewing modes, chose top view, set perspective to 0, set UCS to World, in summary, did everything possible to get a regular 2D planar view, but nothing worked.

I thought it might be some issue with my AutoCad file, so I tried to open some of the sample files that are part of the trial package, but they are also displayed slanted.

How on earth can I convince DraftSight that my drawing is pure 2D and open it as expected?