I have upgraded an older site to 2.3.3 to be able to use DataObjectManager and SortableDataObject, butt too bad, all I'm getting very often (especially on popups, but also eg in versions on the left side) is "Action 'admin' isn't allowed on class CMSMain", which drives me kinda mad, have seen this in older version too sometimes and never seen any descent solution to it.
Using Firebug shows that all the ajax calls seem to return a 403...
so if anybody has some advice on this, i'd be very thankful, because it makes the whole site quite unusable right now!