For the past two days, the website was partially available and mostly offline due to the issue that occurred during the upgrade process to the new version of CMS.
The issue was affecting only a small amount of websites and it seemed completely harmless. 

It's still unknown what is the cause of failed installation.

While the backups are always there and could've been restored immediately, there was an issue with getting the backup in the working condition due to another problem. This took an extra day to fix.
This is, for sure, a lesson learned: Regardless of how seemingly harmless the update is, it should always be tested first before being released live.

We're back in order now and we still have all the upcoming tutorials and goodies for you!