NavData RegistrationFailed_AgentNotValid

I have a super simple character blueprint which I want to send to a location. The navmesh looks as expected but when I try to fire the SimpleMoveToLocation node the char doesn’t move and the log shows the following message:

NavData RegistrationFailed_AgentNotValid, NavData instance contains navmesh that doesn’t support any of expected agent types.

What does it mean and how do I fix it?

If you go to Project Settings > Engine > Navigation System you should be able to find a section called Agents.

Essentially, in order for the navigation system in Unreal to work, it has to have a specific agent associated with it. The agent is simply a way to tell UE4 properties about your navigation. For example, how much space a character needs for a narrow passageway to be traversable, etc. Based on your error, it seems that your navigation isn’t picking up on that agent.

If you have only one Supported Agent defined then you shouldn’t have to do anything else. All AI agents will use the one and only navmesh. If you have more Supported Agent NavigationSystem will pick “best fit” for your AI (one that will guarantee not getting stuck, if possible).

First, I would rebuild navigation to make sure it’s not just a weird glitch. Second, I would check to make sure you have an agent defined in the project settings as I mentioned. If you do, I would delete it and make a new one (you can copy the settings from a default project if you don’t know what to put).

Hopefully that helps.

Cheers,
mmmmGoodDinner

I did try that, setting up agent sizes properly, but it did not help. Eventually I narrowed down the issue to the landscape: as soon as I turned off its “Used for navigation” stuff started working. (Fortunately I could replace the ground with a static mesh collider.) For now I have the “Supported agents” array empty, as seen on the example content level. Will investigate further when time allows.