Hello @ranplayer, in Steam, go to your Library, search for Proton, and go to the game-specific properties for Proton 4.11. From there you should be able to go to the Local Files tab and Verify integrity of tool files....
Does that resolve your issue?
It worked ! Thanks @kisak-valve
proton 4.11x1 2020-09
Your system information
Please describe your issue in as much detail as possible:
I accidentally removed an older Proton version (4.11-13) set for a given game. Steam is not downloading the version again when I try to launch the game.
Steps for reproducing this issue: