No Plugins Menu on Pro Sites Dashboard

Hello, i have a multisite installation with Prosites and "Pretty Plugins" enabled, in Premium Plugins Tab i have some plugins set to Premium, others to Anyone and some enabled by default.
But on the individual sites on the dashboard site menu the plugins menu entry does not appear, if i go to it sayd "you do not have sufficient permissions..."

Could you please tell me what i'm doing wrong?

thank you