On one of my machines I use the ArchLinuxArm packaged version of Anki which happens to be 2.1.15. I noticed that the changes page reads
After using the latest version, if you wish to open your collection with an earlier Anki release, please go to the File>Switch Profile menu item, and click on “Downgrade & Quit”.
The latest version is 2.1.26, but the downgrade function seems to be months old. What is the latest version of Anki I can use without downgrading (assuming one of my clients is stuck on 2.1.15)