Nextcloud version _ 12
Operating system and version - Ubuntu 16.04
PHP version 7
Is this the first time you’ve seen this error?: yes
The issue you are facing:
I had a nice working version of 12. Today I changed update to daily and found a new daily build of version 12. I clicked to install and it seemed to install fine. However when clicking to proceed I get this message
The files of the app Gallery (gallery) were not replaced correctly. Make sure it is a version compatible with the server.
and this leaves me stranded. Advice?
Same error. I did this
sudo mv ./gallery /var/opt
sudo -u www-data php updater.phar (given your using ubuntu/debian)
It installs now fine. But even though, I had it set to daily, It shows nextcloud 13.0 Alpha.
Your previous folder gallery folder could maybe be moved back? I have not done that my self, just yet.
Turns out, it was a mistake to take the upgrade, see Updated to 12 daily and today it wants to upgrade me to v13 alpha?
Edit, just did go trough this process https://docs.nextcloud.com/server/11/admin_manual/maintenance/manual_upgrade.html saved everything, and the install went back to 12.0. no issues.
Set the update channel to stable, and not daily