Dean,
Do you have Xmind 7.5 (plain) or Xmind 7.5 update 1? The former has multiple issues and it is strongly recommended to update to Xmind 7.5 update 1. The update is free/gratis and downloadable at the download page
Do yourself a favour and make a clean install, i.e. uninstall Xmind 7.5 and install Xmind 7.5 update 1 after that.
When it comes to the recovery feature, AFAIK, it is still there and you don't need to specifically activate it, it just is there. (It's a standard Eclipse feature and I see no reason for Xmind to disable it.)