Button new member in project configuration doesn't work
I installed Redmine 3.3.3 last week on RedHat server and I can't add a new member to a project from project configuration or user configuration. List of user or project is empty and button "new member" or "new project" display loading but no effect.
If I create project with a non-administrator user, this user become member by default but I can't add other user.
I'm new to use Redmine and I don't know if this function works with basic install or if I have to add new code.
My env :
Redmine version 3.3.3.stable
Ruby version 2.4.1-p111 (2017-03-22) [x86_64-linux]
Rails version 4.2.8
Database adapter PostgreSQL
no plugin installed
Thanks for your help