I have been getting this error when I save fields to a content type that I have created. Here is the error.
Notice: Undefined index: title_value in link_field_update_instance() (line 1305 of /var/www/foo/public/sites/all/modules/link/link.module) – note the path may not be the same for you.
Here is the issue summary:
There is a patch listed here. very easy to install manually. and fixed the issue.