RVNC viewer Raspberry pi 4 gray screen problem

I was using my Raspberry Pi remotely via VNC Viewer on my iPad without any issues. However, after I deleted all the Python files on the Raspberry Pi, I encountered an 'Error: The port on which the computer is listening for a connection could not be contacted' issue. I managed to resolve that error, but when I tried connecting to the Raspberry Pi via VNC again, I was only able to see a gray screen instead of the desktop environment.