There was a configuration error in the default htmleditors_config.xml

Looks like Jahia tries to load something in the corporate_templates and not in the corpv2 (I am using the corpv2)

I now have a JSS error when tryint to enter a new blog entry (with IE6) when goiing into my blog main:content on the build 18510 (cf screenshot)

The editor combobox was moved below the editor.

The CSS combobox was removed completely. We do not offer the functionality anymore to let the editor choose a CSS.
The CSS is still determined via the htmleditors_config.xml. The list of available CSS is parsed and the first CSS which maches the template is taken (selectors are either the <allowed-sites>, or if the CSS is <shared> then also the <allowed-templatesets> could be determined). You can reference a CSS within the site's template structure and you can use a %SITE_NAME% placeholder instead of the sitename.

If you want to overload the automtic determination of the CSS, you can also set a specifc CSS to a BigText, by setting a field property, like this (taken from the blog definition):

<%
jData.containers().declareFieldDefProp("blogBody",
JahiaFieldDefinitionProperties.FIELD_STYLESHEET_ID_PROP,
"corpv2_blog");
%>

You have to make sure that there is an entry for the key "corpv2_blog" in the htmleditors_config.xml.

Beside the CSS file, which will be used in the editor, In this configuration file you could also set the styles definition XML file, which controls which styles are displayed in the combobox by the FCKeditor.