Trying to run python script using the "Unity" engine does not compile as "%1 is not a valid Win32 application"

[Caerii]

Trying to run using the "Unity" engine creates this error. Python 3.9, windows 10.

self.proc = subprocess.Popen(launch_command, env=environ)
File "G:\PythonThings\anaconda3\envs\simulate39\lib\subprocess.py", line 951, in init
self._execute_child(args, executable, preexec_fn, close_fds,
File "G:\PythonThings\anaconda3\envs\simulate39\lib\subprocess.py", line 1420, in _execute_child
hp, ht, pid, tid = _winapi.CreateProcess(executable, args,
OSError: [WinError 193] %1 is not a valid Win32 application