The agent is unable to process the webagent.conf file because of line breaks in the arguments to the agent form parameters.  For example:

cleartrust.agent.login_form_location_basic=http://<hostname>/login/login.jsp?CTAuthMode=BASIC&language=<%languag
e%>

Because the line break exists in a substitution tag (e.g., <%language%>), the agent errors out on processing the file, and prevents Apache from starting up.

Note that this is a different problem from the agent failing to start because of missing configuration parameters, in which case Apache still fails to start, but reports a misconfiguration with the parameter name.