Follow these steps to replicate (Screenshot of end result provided)
(1) Go into Social Office
(2) From Dashboard select a site you have rights to modify a document
(3) Go to the document in the sites document library
(4) checkout the document
(5) Go to Edit Screen (Not Edit online)
(6) From the pop up window select a different value in the Document Type field
This will cause a screen to appear as seen in screenshot. Repeatable in all browsers.
Either only the pop up is reloaded with the correct content, or no pop up is used for editing and Edit opens as standard full portal URL.
The behavior is caused by customized JSP in so-hook -> META-INF/custom_jsps/html/portlet/document_library/view_file_entry.jsp. This hook, in comparison to stock 6.1.20 DocLib JSP, uses popup after clicking on Edit button (in detail of some document). But in the invoked edit_file_entry.jsp (used to render the edit of a document) is used following construct to render the available Document types:
<aui:select changesContext="<%= true %>" label="document-type" name="fileEntryTypeId" onChange='<%= renderResponse.getNamespace() + "changeFileEntryType();" %>'>
The problematic part is changesContext="<%= true %>", which reloads the whole page, when you change the documetn type – it does not know that it's rendered in a popup. This causes EXCLUSIVE portlet URL (used to render the popup) to be rendered in the browser, causing no CSS etc., see screenshot.