Importing geometry form AutoCAD

Hi, 

I accurately prepared the geometry in CAD and generated both PL and Regions. I tried to import the geometry and the import was successful. The problem is whenever I import the geometry Plaxis will detect a side of the model Fix, and another side free like a slope. I tried to manually change the boundary condition, but manual keys don't work properly and have no action on the model. 

My geometry is complicated and is not easy to define by hand. It is an outcome of surveying.

I look forward to receiving any help. 

Best regards,