Overview 

This article describes the process to follow when Microsoft Internet Explorer cannot load certain webpages when passing through GFI WebMonitor. The following error message is displayed:

HTTP Error 406 - Not acceptable

Process

Environment 

• GFI WebMonitor 
• All supported environments

Root Cause

The GFI WebMonitor can only process plain text encoding and that's why it sends the request to the Web servers with Accept-Encoding: FFFF, FFFFFF header, but certain web servers do not accept this kind of header value, hence return a 406 error to the HTTP client.

Process

Configure the browser to avoid changing the Accept-Encoding header by GFI WebMonitor.

1. Open Internet Explorer.
2. Navigate to Settings > Internet Options.
3. Click on the Advanced tab.
4. Uncheck the HTTP 1.1 through proxy connections option.