The directions could be much better. Many of the reviews refer to a very common mistake. Let me boil it down so you don't make the same mistake that everyone else did.
1) Don't install the cross bars until the frame is fully assembled. This will make fixing issues (which point 2 will help you avoid) much easier.
2) Important: The top of the ladder attaches to the upper frame via a bolt. The frame has a small threaded hole to accept that bolt. The hole MUST be on the bottom side of the upper frame. If the hole is on the top, you messed up and the ladder won't connect correctly.
Simple assembly advice
The directions could be much better. Many of the reviews refer to a very common mistake. Let me boil it down so you don't make the same mistake that everyone else did. 1) Don't install the cross bars until the frame is fully assembled. This will make fixing issues (which point 2 will help you avoid) much easier. 2) Important: The top of the ladder attaches to the upper frame via a bolt. The frame has a small threaded hole to accept that bolt. The hole MUST be on the bottom side of the upper frame. If the hole is on the top, you messed up and the ladder won't connect correctly.