There is a new guide that references all of the errors that we see each and every day.
This guide lists the high and critical severity run-time errors for the webMethods Integration Platform, gives explanations for the causes of the errors, and recommends actions a user can take to remedy them. It contains information for system administrators responsible for the operational health of the webMethods Integration Platform to enable them to monitor and react to errors and events. The book is also useful for developers who are responsible for error handling.
FYI for those who can get to advantage, go to webMethods Integration Platform-wide documentation.