Application throws error on Docbase when trying to save document after making changes in Ckeditor

1. Go to experience manager perspective
2. Go to event tab
3. Click content field
4. Select any word or number of words
5. Try to add link to selected words
6. Select documents from different channel
7. Click ok
8. Click save button

Actual result : Error appear when user try to save document

Expected result : User should be able to save the document without any error

Recording

 Note : When user remove exisiting docbase field from event document type thn user is able to save document successfully.