Paths are not quoted, leading to errors if folders have spaces.

[VocalFan]

The directory was C:/Users/Windows Games/Downloads/Kyty/fc_script.exe
For which, to allow spaces, the path should be quoted when sent to Command Prompt.
"C:/Users/Windows Games/Downloads/Kyty/fc_script.exe"
Or to REALLY be safe for potential flagging issues, use double backslashes instead of a forward slash.
"C:\\Users\\Windows Games\\Downloads\\Kyty\\fc_script.exe"
The double backslash signifies that it isn't an escape character like \n, but instead a single backslash, like \