Unable to activate and install plugins ..

[whiteatom]

Hi,
 There is a very big problem I am facing with storestacker .. I am
unable to install the plugins here's what I do

1. Unzip the plugins and upload them to plugins directory at the server

2. I go to plugins section from my admin panel and click on "install"
but once I input the details of my affiliate i.d and click on "save",
the status of that plugin is changed to "setup" i do not know how to
change it to installed? this is very frustrating, as I have checked in
"preferences" and there is no option there to enable or disable the
plugins? please help ..