I am trying to assign the combinaison "CTRL+Y" to the "undo" action.
It is not running...

Could you please help me?

Thank you,
Adrien

Have you checked the help info for Editor Shortcuts?

By default, Ctrl + Y is set to delete a line, you may have to disable that one first.

I deleted the "delete a line" shortcut and re-assigned CTRL+Y to the "undo" action but it doesn't work.
Nothing happens when I press it ...

Did you change IDE Shortcuts or Editor Shortcuts?
If you need this to be changed for the editor, you have to use the latter one.

I had to change both of them because CTRL+Y was defined in IDE Shortcuts (for line deletion) and the redo action in Editor Shortuts.