Validation and Error Feedback

PathEngine's 2D content processing has a well defined set of constraints on markup geometry which are applied strictly on export.
While this validation may sometimes seem a bit harsh the advantage is that, once markup geometry has passed the validation stage, the run-time pathfinding is guaranteed to work correctly with that mesh (or otherwise it is a bug).

This means that content creators can effectively 'sign-off' on pathfinding markup once the validation stage has been passed.
(In contrast to other approaches without strict validation, but where problems with run-time agent movement can nevertheless be passed back to content creators requiring content to be re-visited, often at inconvenient times.)

And PathEngine's error checking is designed to provide information about specific geometry relating to each error, as far as possible.
The content integration plugins then provide mechanisms to enable you to quickly localise this geometry, even within complex scenes.
So once you are familiar with the kinds of errors which can arise, and the mechanisms for localising those errors, these errors are generally pretty straightforward to resolve.

See Content Validation for a detailed explanation of the validation constraints applied by PathEngine's content processing functionality.

Providing an efficient content process is considered very important for PathEngine, and the content processing is continually being improved, to remove or relax constraints where this is possible, and to provide clearer information about errors that do occur.
So if there are specific errors that occur frequently within your specific content process, and which look like they could be provided, then it can be worth talking to PathEngine support.

Errors due to approximation to integer coordinates

Validation is applied after rounding to integer coordinates.
Very small faces may becoming zero area (or downward facing) and therefore failing validation is a fairly common problem, that can often be resolved by choosing a different coordinate scale.
Refer to Integer Coordinates and Approximation for a more detailed discussion of this issue.