I install plugin and configure admin user. It works fine. 

But when I restart Jenkins, admin users keep having admin role but admin stuffs not accessible, I get an access denied error. 

I get the same problem with any other configured user. Users keeping their roles in config but Jenkins (the plugin) doesn't give access to any role. 

User are managed using : "Jenkins Own User Database"

In other to make it work, I need to kill Jenkins, delete config.xml file and restart it again with new configuration. 

With version 3.0, Jenkins fails to start. 

Thank you for helping.