Steps to reproduce on XE 5.4.4 (Tomcat 6 + MySQL):
- edit any page with Wysiwyg
- click on "Link" -> "Wiki page"
- click the "All pages" tab and see that you cannot scroll down because the vertical bar gets stuck and the tree overlaps the page name input (see the attached screenshot)
I couldn't reproduce the issue on IE10. I don't know whether that's relevant, but I tested on a wiki with ~ 9000 documents.