Open Radar

 
Closed as duplicate of 14761252

Summary:
Since installing OSX Mavericks, the Safari web browser has not been able to access internet websites through a corporate Proxy Server.  All variations of proxy settings have been tried.  On occasion, a web page, or partial web page, will be returned but it takes at least 30 seconds (not a network issue as other browsers respond to the same URL in a few seconds).

Steps to Reproduce:
1. Ensure you are using a proxy that is configured with NTLM authentication (such as Forefront TMG)
2. In the Proxies tab of Network Settings use either "Auto Proxy Discovery" or manually enter your HTTP and HTTPS proxy settings
3. Attempt to access a website that is known to be firewall-restricted

It has been observed that clicking a link in an external application, such as Apple Mail, will sometimes succeed after considerable time - yet the same link will not succeed if typed directly in the browser.

Expected Results:
The website should respond in a similar manner to other browsers.

Actual Results:
URL progress bar will continue for up to a few minutes.  Some parts of the web page may eventually be displayed.

Version:
Safari 7.0 (9537.71) - no extensions installed
OS X 10.9 (13A603)

Notes:
This behaviour is not evident with the following browsers:
- Opera
- Firefox
- Chrome

All prompt for proxy credentials, remember them, then connect to websites successfully.

Also - embedded Safari related functionality such as Shared Links does not work.

This may be a common problem. eg. see:
https://discussions.apple.com/thread/5469717