I have a client site due to golive today ... well it was due to ...
We reordered pages using the drag and drop functionality in the CMS site tree. Some pages were moved into their parent level, others may have been moved into their child level. Now the site tree won't open a section, it just displays a spinning symbol and i get an Internal Server Error message with growl.
Try to set up a log file to see if there any more info there.
I'm guessing the drag and drop functionality has tangled up the database - it should be impossible to drag a parent into a child section surely?
As a follow up to this, I'm not certain of my hypothesis above, certainly the ParentID reordering fixed my problem, but i suspect the cause is that when an item is moved in the CMS Site tree - a 'modified' message appears next to the name ... if this page is not saved and further reordering occurs then BAM! The site tree locks up.
So this seems to me to be quite an important problem for SS to fix - relying on people to manually save files once moved in the site tree before making further edits is not in my view intuitive (and a 'modified' message does NOT communicate the need to open and save the page). If a user moves an item in a drag and drop display that act should complete the process - there shouldn't be a need to open and save that page.