Fx91: @mozilla.org/plugin/host is undefined

Uncaught TypeError: Cc['@mozilla.org/plugin/host;1'] is undefined
    torbutton_toggle_plugins chrome://torbutton/content/torbutton.js:1132
    torbutton_do_startup chrome://torbutton/content/torbutton.js:1375
    torbutton_new_window chrome://torbutton/content/torbutton.js:1480