The Route via HTTP(S) Assertion fail with Message:
Message was not processed: Error in Assertion Processing (601)
The problem is caused by the Proxy configuration of the Route via HTTP(S) Assertion.
The Assertion fails because it requires a Proxy Username and a Proxy Password to be set.
The Proxy credentials are mandatory, also in situations where Proxies do not require Username and Password.
Please set a place holder Proxy Username and Proxy Password to the Proxy configuration of the Route via HTTP(S) Assertion in the case your Proxy does not require User credentials.