CMS Made Simple Forums

I am not sure where to post this error.
I would be grateful for any assistance with anyone who has a possible solution.

Fatal error: Cannot instantiate non-existent class: zend.php in /web/www/colleges/med/departments/eye/admin/editcontent.php on line 435
is displayed only when editing and adding pages.
the site itself and other tools work in cms.

What could possibly be the solution?
upgrade?
I would rather not compound the problem and solve.
Thanks

okay . if there is anyone.. who has the same issue
heres the solution.
lib/classes/contenttypes/
had a zend.php file that is an apparent hack
all is locked now
hope this helps someone