Error on file upload. Error number: 103

Hi,

I have problem on Insert/Edit Images. I'm using FCKEditor for my asp site,
Version 2.6.

web server is windows based.

in Image Properties -> Upload, after browsing for jpg image, then I click on "Send it to the Server"
, then it prompted error:
Error on file upload. Error number: 103

Do you know how to fix that ?

I checked following:
..\fckeditor\fckconfig.js
var _FileBrowserLanguage = 'asp' ; // asp | aspx | cfm | lasso | perl | php | py
var _QuickUploadLanguage = 'asp' ; // asp | aspx | cfm | lasso | perl | php | py

..\fckeditor\editor\filemanager\connectors\asp\config.asp
Dim ConfigIsEnabled
ConfigIsEnabled = True

Dim ConfigUserFilesPath
ConfigUserFilesPath = "/userfiles/"

What else ?

Regards,
Skywalker