Similar problem https://forum.audacityteam.org/t/so-i-just-want-to-get-the-capabilities-of-audacity-like-i-remembered-it/65745/7 apparently solved.
Rather than “purge”, (i.g. delete), I would rename “pluginregistry.cfg”, to, say “pluginregistry-old.cfg”,
so you have the option to go back to the previous state.