Rudder

I upgraded rudder 4.3.10 -> 5.0.17 -> 6.0.5 -> 6.1.0 beta 3 to get support for last os.
When I reached 6.0.5, I encountered a reporting bug and so I switched to 6.1.0.beta3. But now, I have a problem with technique, I can't reach the page and I get:
_An Error occured! Error while fetching methods
Details:

Could not get generic methods metadata <- Inconsistency: An error occured while updating generic methods library,
error out:
std out:_

In logs, I get:

2020-05-15T11:58:17+0200 WARNING Failed to execute shell command from Rudder: error=2, No such file or directory[2020-05-15 11:58:17+0200] ERROR com.normation.rudder.rest.RestUtils - "Could not get generic m ethods metadata <- Inconsistency: An error occured while updating generic methods library,\n error out: \n std out: "

Techniques still work.

What can I do?

Original message:

Bonjour,

Afin de prendre en compte les derniers OS, j'ai effectué un upgrade de rudder.
4.3.10 -> 5.0.17 -> 6.0.5 -> 6.1.0 beta 3
Quand je suis arrivé en version 6.0.5, j'ai eu le bug de reporting qui m'a incité a passé en 6.1.0 beta 3.
EN 6.1.0 beta 3, j'ai un problème pour accéder à la partie techniques. Cette page n'est plus accessible avec le message :
_An Error occured! Error while fetching methods
Details:

Could not get generic methods metadata <- Inconsistency: An error occured while updating generic methods library,
error out:
std out:_

Si je vais dans les logs, j'ai ceci :

2020-05-15T11:58:17+0200 WARNING Failed to execute shell command from Rudder: error=2, No such file or directory[2020-05-15 11:58:17+0200] ERROR com.normation.rudder.rest.RestUtils - "Could not get generic m ethods metadata <- Inconsistency: An error occured while updating generic methods library,\n error out: \n std out: "

Mes tehcniques précédemment créées fonctionnent toujours...

Une idée??