Please Help: I have used CK editor but it is not showing preview in modx where as the default editor is seen always.

I am using Modx revolution 2.5.1-pl please help i tried reinstalling CK editor through package management multiple time. This problem is arised, once i unknowingly fdeleted the core folder but later i setup again to it and core folder is back but the CK editor view is not back

Hi! sorry I see your post laste,
I had the same problem, since ckeditor adds some files inside the manager folder when upgrading, it may happen to overwrite everything.
I solved re-installing the package.