get input{
  player.alias = result
}

Error running script: Error compiling expression 'result': Unknown object or variable 'result'

are you using Game Book or Text Adventure? (if you're using Game Book, maybe it just doesn't have this feature, but I don't know Game Book that well, and am too lazy to look it up, lol)

otherwise, something is wrong with quest's coding... either you changed/messed it up (or over-written parts of it) or someone else changed/messed it up (you're using a different language of quest and they didn't code it correctly or you downloaded a bad quest file/s, for examples)

if it might be something you've done within the user level, then you can paste your game code here, and we can fix it up for you.

if you've changed quest's underlying code (Filter -> Show library elements ~OR~ you altered the actual quest files directly)... unless you can tell us exactly what you did... it'd be easiest to just re-download quest...