If it used to work and you haven't installed anything new, chances are your AV updated its db and recently started flagging Plutonium as a virus, thus probably blocking the bootstrapper.
Try adding it to exclusions - https://plutonium.pw/docs/antivirus/
If you use an extremely intrusive AV such as mcaffee, avast, etc, you should probably uninstall them and restart your PC since they don't really respect your exclusions.