I have the same problem with a similar English display whenever handing a file to Photoshop as external editor. This is my understanding. Photoshop CS5 Extended cannot use ACR 8.6 it stops at ACR 6.7(?). Lightroom 5.x operates using newer ACR technology versions. Updating ACR beyond 6.7 is not possible without updating Photoshop to CS6 and all that that implies with Creative Cloud etc.
You have to 'Rendu dans Lightroom'. (Ne plus afficher - not part of my display - presumably would make the Rendu dans Lightroom the default action.
I remain uncertain as to whether there are significant or substantial disadvantages to doing continuing to use Lightroom in this way.