Unlike more realistic hacker games; with hacker sim apps/scripts can only be run when on the local computer. If you bought nmap from the store, you likely accidentally put it on the server.

Open the serverzilla app, in the right window "server", click the tool folder. If nmap is listed, select it and press the left arrow to transfer it back over.

had same issue. in my case, you're spot on. makes complete sense, too. thank you for sharing solution!!

i think i know why it doesn't work and the reason is that this is a free trial so it's really limited so if you wanna do real mission's you have to buy the game and not just play the free version