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Errors within Katana scenegraph traversal are indicated (from Katana or the scene recipe) by an "errorMessage" attribute at that location. A fatal error is indicated when the location "type" has been set to "error" or if the attribute "errorSeverity" has been set to "critical". RfK will skip over error locations by default, which can result in missing geometry in the render.  If you want RfK to abort the render when it encounters an error location, you can set the prmanGlobalStatements.errorHandler to "abortall".  With this attribute set, all error locations will cause an aborted render. However, if you wish to have more control over the specific errors that should cause an abort,  there is a mechanism by which a custom override handler can be added to intercept and reinterpret the error location. An attribute function can be injected into RfK that will make the final determination of whether a location error is fatal or not. This attribute function runs after RfK has done its work for deriving the error's fatality essentially giving the author the last word.

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Errors in RenderMan contain a error code and error message.  By default, these errors will show up in the Render Log, but the render will not terminate.  You can change the preference for this with the prmanGlobalStatements.errorHandler option in PrmanGlobalStatements.  Setting the value to "abort" or "abortall" will terminate the render.  For finer control, RfK provides a mechanism to override the built in errorHander an errorHander set to abort or arbortall based on specific error codes and error messages.  An attribute function is injected into prman's error handling system to determine if an error should result in termination of the render.

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