IIS 8.5 verbose error – 404.11

Most likely cause:

• The request contained a double escape sequence, and the request filtering configured on the web server rejected the double escape sequence.

Actions to try:

• Verify the configuration/system.webServer/security/requestFiltering@allowDoubleEscaping setting in the applicationhost.config or web.confg file.

Detailed error message:

details:

This is a safety feature. Please do not change this feature unless you are fully aware of the scope of the change. Before changing this value, a network trace should be done to confirm that the request is not malicious. If the server allows double escape sequences, modify the configuration/system.webServer/security/requestFiltering@allowDoubleEscaping setting. This can be caused by a malformed URL sent to the server by a malicious user.

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