To me it seems that asp connector in the 2.6.3 is completly out of order.
After configuring as decribed from manual and lot of test with paths I started to analize the source code.
1) The file class_upload.asp is a unicode file and generate same problems in the ascii editors (and quite sure to vbscript)
2) The file basecml.asp, line 33, contain Response.CodePage=65001, but that generate error in VBscript, the same as writing response.inexistentAttribute or response.helloeverybodywhatareyoudoing?
I only use Php or Asp classic... but suppose that assign codepage that way is only working in aspx not asp where it should be used <%@ CodePage=65001 Language="VBScript"%> instead.
Trying to fix all, calling the connector manually (to understand what's going on), passing the same parameters I see on the "upload images - Browse serverr" I stopped here:
XML Parsing Error: not well-formed Location: http://192.168.0.3/beni/fckeditor/editor/filemanager/connectors/asp/connector.asp?Command=GetFoldersAndFiles&Type=Image&CurrentFolder=%2F&uuid=1227200675432 Line Number 1, Column 1:/beni/public/userfiles/image/ /beni/public/userfiles/image/ ^