Hi all! I made a nice GridMap level and I want to add some navigation mesh onto it. I can put down the navmesh just fine, but when I go to run the program I get an error that I can't find how to fix. I get a red error:

"E 0:00:01:0063 sync: Navigation map synchronization error. Attempted to merge a navigation mesh polygon edge with another already-merged edge. This is usually caused by crossing edges, overlapping polygons, or a mismatch of the NavigationMesh / NavigationPolygon baked 'cell_size' and navigation map 'cell_size'.
<C++ Source> modules/navigation/nav_map.cpp:845 @ sync()"

It sounds like I have some navmesh that is overlapping itself, but I can't find how to fix it. Has anyone ever encountered this?

3 months later

Just set the cell_size in navigationregion2d node and in project settings set navigation-> 2d to the same as cell_size but keep cell_size lower i.e 1 to 10 because it helps in path finding but if we increase it too much pathfinding will be difficult for agent.