Index: _source/plugins/wysiwygarea/plugin.js
===================================================================
--- _source/plugins/wysiwygarea/plugin.js	(revision 5812)
+++ _source/plugins/wysiwygarea/plugin.js	(revision )
@@ -891,8 +891,15 @@
 							{
 								if ( isLoadingData )
 									isPendingFocus = true;
-								else if ( editor.window )
+								// Temporary solution caused by #6025, supposed be unified by #6154.
+								else if ( CKEDITOR.env.opera && editor.document )
 								{
+									editor.document.getBody().focus();
+
+									editor.selectionChange();
+								}
+								else if ( !CKEDITOR.env.opera && editor.window )
+								{
 									editor.window.focus();
 
 									editor.selectionChange();