Digital Lock simulation not working

Sir, I tried to simulate the digital lock assembly code provided on your website here: http://www.8051projects.net/download-d206-digital-lock-using-at89c2051-lcd-keypad-assembly.html

When I simulate it, the LCD display "Enter your code:" but when I press any key on the keypad two things occur:
1. It does not show the entered input digit on the LCD
2. The column pin for that specific digit becomes invalid (shows state= GRAY)

Snap shots are provided below.
The first one is the circuit diagram.
The second one is the initial state (no key has been pressed).
The third one is after the key '5' has been pressed.

Any sort of help will be appreciated. Thankyou!

There is a version of proteus which has issue with 4x3 keypad. You can try to use a different version of proteus to test it or use 4x4 keypad in 4x3 configuration and test again. This project has no issues in simulating.