2021.3.10f1, same issue as Nyarlathothep.

Just doing this in a FixedUpdate causes a log spam to occur:

using (var query = new NavMeshQuery(NavMeshWorld.GetDefaultWorld(), Allocator.Temp))
{
}

Using or not using the query doesnt matter.

Following on from my earlier comment, it looks like using TempJob instead of Temp fixes the issue.

I'm seeing this a lot in 2019.2 - it seems to be caused by using short lived queries.

In an ECS system that create/destroys a NavMeshQuery when the system is created/destroyed (i.e. long lived) I don't see the errors. On the other hand if I do something like:

using (var query = new NavMeshQuery(nav, Allocator.Temp, 512))
{
// Some work
} // <--- error here

I get an error on the closing brace, i.e. when the query is disposed.

The errors will keep spamming the console until the entire editor is restarted.

Same error happening on 2019.3.0f1. Can't tell if it's the same issue as there is not enough info in the above report.