The following error message may appear:
"HTTP 403.5 - Forbidden: SSL 128 Required Error Occurs with Require Secure Channel Option Disabled”
When you enable the 128-bit SSL requirement in conjunction with the general SSL requirement, the 128-bit SSL requirement remains enabled until it is explicitly turned off (independent of the parent SSL requirement)
To solve this issue, please ensure you run the following steps:
Open the Internet Services Manager then right-click the problem Web site and click Properties
Click the Directory Security tab; click Edit close to Secure Communications.
Click Encryption Settings, click to uncheck the Require 128-bit encryption check box.
- Click three times on OK button to close the dialog boxes.
More info here: http://support.microsoft.com/kb/308255