I added this to a post here on the forum to help people out.
https://www.pbxforums.com/threads/updating-source-git-issue.4026/
For convenience here it is again.
If you run Advanced -> Upgrade -> Source or when using git pull.
May receive message like
- Your branch is ahead of 'origin/master' by 15493 commits.
- CONFLICT (content): Merge conflict
The following will fix this issue.
cp -R /var/www/fusionpbx /var/www/fusionpbx-20200327
cd /var/www/fusionpbx
git fetch origin
git reset --hard origin/master
git pull
chown -R www-data:www-data /var/www/fusionpbx
WARNING: This will work for most people. Un-tracked files should be safe. However if you manage your own customization's for files tracked by Git you will likely need to do more to fix this issue.