Can't access settings of plugins in Tool Admin

I have tried disabling newly installed plugins to see if any are causing a conflict, but no joy.

I can access Tool Admin, enable and disable plugins, but cannot access the seettings for riverdashboard, tidypics, eventcalendar, siteaccess.

Not sure if it's related, but can only access events by clicking on the link in the river, but not when clicking on the event in the calendar view...

Where do I start looking to fix this?

Edit to add: The link to add a site wide message to the river can also not be accessed.