Either your host hasn't enable the zip or gzip module (Cant rememebr what it is called) or it is something else I cant think of. Oxwall dev will be able to put the finger on this tomorrow.

the host told me that the zip module is enabled

When I install the plugin manually, the plugin is installed but not the language. Why?

meybe cuz you remove or modify default english language
dont touch english language never

@Leo : What ?

with all that I want to install

there are no values

I installed the pluggin (s) manually and when I look in the admin ...language ... the pluggin installed is not in the list.
But I'm still not the answer to my error message : admin + manage_plugin_add_extract_error

ow_pluginfiles
ow_plugins
ow_userfiles

Chmod 777

what screenshot ?

with all new pluggin
This error occurred since I spend on a vps hosting

my ftp settings are correct because I know deleted via the admin panel pluggins installed manually

Install ...no
Uninstall and Delete ... yes

It works
Thanks

I did not set chmod 777 to subfolders