Camera RAW ne s'ouvre pas

Did you install Camera Raw from the Help menu?  If not, that's all you need to do.   You can install Camera Raw from either the Organizer or the Editor.  Once you start the installation, you may get a message that you need to close all open Adobe applications.  If that happens, close the program from which you started the Camera Raw installation.

Do this, then you will good. HOWEVER:  attempt to open any image with ACR- and you will be promted to install it- which is more than enough of whaat you need.

Download and install the latest Camera Raw version from https://helpx.adobe.com/camera-raw/kb/camera-raw-plug-in-installer.html

Quit all Adobe applications.

On macOS, double-click the .dmg file to mount it.

On Windows double-click the downloaded .zip file to unzip it.
(Windows might unzip the file for you.)

On macOS, double-click the .pkg file to start the installer. 

On Windows, double-click the resulting .exe file to start the installer.

Follow the on-screen instructions.

 Once installed successfully, close the installer window.

 Navigate to the following folder:

On macOS: /Library/Application Support/Adobe/Plug-ins/CC/File Formats

On Windows: C:\Program Files\Common Files\Adobe\Plug-Ins\CC\File Formats

Copy the Camera Raw plug-in (just the .8bi file) from the CC > File Formats folder that is mentioned in the above step.

Navigate to the following folder: 

On macOS: /Library/Application Support/Adobe/Plug-ins/Elements<Version Number>/File Formats

On Windows: C:\Program Files\Common Files\Adobe\Plug-Ins\Elements<Version Number>\File Formats

Replace the existing Camera Raw plugin in Elements<Version Number> folder with the plug-in that you copied earlier.