We have a problem on a Typo3 where the topbanner sometimes appears in the right column on top of / replacing another element.
The problem happens on frontend on different pages. There is apparantly no pattern in the error.
See screenshot on same page here, where the error is there and 2 minutes later isnt:
[url removed, login to view]
If you keep on clicking on [url removed, login to view] the error will come on around every other load.