I started creating a map in the editor with KB and Mouse. I then saved and did something else. When i came back to continue editing, upon loading the map i get this error message (1).
And then it just completely erases everything and goes into controller editor mode (2) even tho the map was never edited with a controller or any controller is plugged in the first place!!
What am i supposed to do now?

(1) https://imgur.com/a/4UFRv8D
(2) https://imgur.com/a/vKKJxad

Can you share the map file here, so we can take a look?

Also note that the advanced keyboard & mouse editor regularly saves the map as you're mapping, so you'll have backups of the map in the Documents\Trackmania\Maps\Autosaves\ folder.

However, if you believe the issue you experienced is a game bug, you'll need to report that on Ubisoft Discord, as TMX forums are community forums.