Originally Posted by
GKEnialb
That does look like it may be coming from Token Height Extension. The really odd thing is that I don't override getGridSize (even though I am overriding image.lua), so not sure why it would disappear in the middle of a session, especially as the map isn't being changed (in the example that bmos linked to). In the meantime, I put in a semi-workaround where it tries to continue if it fails to call getGridSize().
kevininrussia, if you can list your other extensions and your rulesset, I'll try to dig deeper.