I've validated server and client versions are the same, and still can't interact with doors and ladders. My mouse pointer is a dot instead of the 4 quadrant circle. Also running Windows 8.1 x64. Happens regardless of server. I can interact with items on the ground and pick them up with the mouse. I even deleted and reinstalled from steam, no luck.

same. I've validated my client and servers "match". I even removed and reinstalled from Steam.