On update, error with local repository

I'm running PiHole on a Raspberry Pi 2 under DietPi v159 (the latest DietPi release.) I went to update PiHole on 31 Dec 2017 and received the following error:

Error: Could not update local repository. Contact support.

Unable to complete update, please contact Pi-hole Support

My PiHole installation is fairly vanilla; all I have done is added the repository "https://v.firebog.net/hosts/AdguardDNS.txt" to the block lists. Any idea on how to address this error?

Thanks

What is the output of

cd /var/www/html/admin;git status 
cd /etc/.pihole;git status 

show?

Jacob

Wonderful, how have showed me how to do the update properly.

showed that everything was up to date. However,

showed all kinds of modified issues, as follows:

pi@atlantis:/etc/.pihole $ cd /var/www/html/admin;git status
On branch master
Your branch is behind 'origin/master' by 2348 commits, and can be fast-forwarded.
(use "git pull" to update your local branch)
Changes not staged for commit:
(use "git add ..." to update what will be committed)
(use "git checkout -- ..." to discard changes in working directory)

modified:   .github/ISSUE_TEMPLATE.md
modified:   .github/PULL_REQUEST_TEMPLATE.md
modified:   .gitignore
modified:   .pullapprove.yml
modified:   .user.php.ini
modified:   CONTRIBUTING.md
modified:   LICENSE
……

I followed the suggestions in the following website to address these modifications prior to the update:

I also saved the lighttpd.conf file as suggested on the DietPi forum website:

And once I did so the update worked great.

Thanks for the help.