[✓] Check for existing repository in /var/www/html/admin
[i] Update repo in /var/www/html/admin…
Error: Could not update local repository. Contact support.
*** [ DIAGNOSING ]: Web version
[i] Web: v3.1 (How do I update Pi-hole?)
[i] Branch: master
[i] Commit: v3.1-26-gd7fcc8e-dirty
You have changes in the web interface directory. Remove them (or run sudo git reset --hard in the directory) and try again.