Troubleshoot with Plugin functionality

Have used wordpress in many of my sites, however with the one i am currently working on (through a different host than usual) i have encountered a problem with my Plugins.

I can install them as usual, (and activate them) however when i try and use them or adjust their settings they aren’t showing up on my control panel. Their respective effects aren’t showing on the site either and it is very annoying… please help.
(btw i have also had a lot of trouble with permissions and have fiddled with a couple of folders here and there.)
Thanks