Roundcube + vacation plugin

Hello all,
since few days i try to setup a vacation plugin on roundcube but can not success on this task.
config :
centos 7.3.1611
webmin 1.831
virtualmin : 5.07
roundcube 1.2.3

does anybody know how to configure the plugin correctly (i’m using this one right now : but it does not save the value)
Really thanks for your help