官方补丁：http://dev.fckeditor.net/attachment/ticket/2115/2115.patch
.net 架构解决方案：
Open the file FileBrowser > FileWorkerBase.cs

Go to line 119

Replace: Response.Write( @"(function(){var d=document.domain;while (true){try{var A=window.top.opener.document.domain;break;}catch(e) {};d=d.replace(/.*?(?:\.|$)/,'');if (d.length==0) break;try{document.domain=d;}catch (e){break;}}})();" );

Replace with: Response.Write(@"(function(){var d=document.domain;while (true){try{var A=window.parent.OnUploadCompleted;break;}catch(e) {};d=d.replace(/.*?(?:\.|$)/,'');if (d.length==0) break;try{document.domain=d;}catch (e){break;}}})();");

Compile the project and then reference the new dll file in your project.

Fckeditor 2.6 上传失败 asp.net 解决方案 OnUploadCompleted permission denied