Slug reversed & plugin will not update

Good morning, 

Our Forum has ceased working, here are the issues we would like assistance with in hopes that it will fix our forum:

  1. We are getting this alert in the admin area: "Permalink Conflict! Please change permalink for the "Forum" post, the "forum" slug is reserved." However, when we go to that page, the slug is "forum" and when we check the settings the forum page is set to "forum." Please advise on how to resolved.
  2. We've been attempting to update our ForumWP plugin but continue to receive the error "An error occurred while updating ForumWP - Pro: Download failed. Unauthorized." We have the correct license key attributed. 

We're looking forward to hearing your suggestions on how to resolve this. 

Thank you,