You have this problem because the script for lol is out of date, while it does not update it is necessary to use a hotfix for the cheat to work, I will leave a tutorial along with the download of the hotfix
1- You need to open the game client
2- Go to the folder C: \ Riot Games \ League of Legends \ Game
3- Paste the hotfix files and replace.
O.B.S: You must replace the files with the client open, otherwise it will not work,
if you change accounts you will have to do the hotfix again and if you use the option "close client during the game" don't worry, you don't need to do the hotfix every time the game ends.