So you're not running litestep as shell then? Make Litestep your shell or use a shellswitcher like ShellOn or Carapace. Works very well! Then try to select theme again.

For a newbie you had better installed litestep on the C:\ drive. This is more save in case the config files were not coded well and hardcoded dir paths were used.

Tried to load Xhenit_V2_OTS myself and works just fine!