When first popular Oracle ApEx versions (like 1.6, 2.0) came out, they had problems with displaying SQL Workshop Object Browser windows on some FF versions, just dont remember which exactly (imho 2.2). Here we are again having the same problem: red screen. This time its new Google browser Chrome. The same problem can be found on ApEx versions 3.0, 3.1 and 3.1.2, havent tested this on others. The common solution back then was to add a few directives to Oracle HTTP_Server's configuration file httpd.conf:
AddType text/xml xbl
AddType text/x-component htc
No luck this time. Anyway, Chrome is just beta, hoping to have a better functionality soon.