Internal clients cannot use Internet Explorer to access FTP sites through Web proxies


Symptoms


When you use Microsoft Internet Explorer to try to access a File Transfer Protocol (FTP) site, you may receive the following error message:
Windows cannot access this folder. Make sure you typed the file name correctly and that you have permission to access to the folder.


Details:
The operation timed out.

Cause


This issue may occur if the following conditions exist:
  • You try to access the FTP site from behind a Web proxy firewall such as the Internet Security and Acceleration (ISA) Server firewall.
  • Folder view for FTP sites is enabled in the Internet Explorer versions that are listed in the "Applies to" section.
When you turn on folder view for FTP sites, the Internet Explorer client bypasses the Web Proxy and tries to send FTP connection requests directly to the Internet. This operation is unsuccessful.

Resolution


To resolve this issue, turn off folder view for FTP sites in Internet Explorer:
  1. Start Internet Explorer.
  2. On the Tools menu, click Internet Options.
  3. Click the Advanced tab, click to clear the
    Enable folder view for FTP sites check box, click
    Apply, and then click OK.