When toggling vanish i get

i have restarted oxide and reinstalled the plugin.

i have restarted oxide and reinstalled the plugin.

My guess is you didn't add / allow yourself to do that.
Did you read https://umod.org/plugins/vanish#permissions ?
This plugin uses Oxide's permission system. To assign a permission, use
oxide.grant <user or group> <name or steam id> <permission>. To remove a permission, useoxide.revoke <user or group> <name or steam id> <permission>.
= If you're not familiar with oxide groups & permissions, then in it's most simple usage you just need to type into console / rcon:oxide.grant user 123567890 vanish.use
(And replace 1234567890 with the SteamID you want, such as yourself)