Navmesh doesn't work, "can be main nav data" keeps getting turned off

“Can be main nav data” in project settings → navigation mesh keeps getting turned off when i restart the editor and also navigation doesn’t work when i package the project.

1 Like

I just found the same checkbox from project settings (can be main nav data) in the recast nav data detail panel in my map and checked it. Now it saves the setting and it works with builds too. Its just weird that “Project Settings” doesn’t save that setting but recast nav data does.

I’m having the exact same problem, except checking the “can be main nav data” in recast does nothing. I could work around this except the problem also still persists when I package the game as well. Was there something else that made yours work maybe? I also noticed that changing anything in project settings overwrites the same thing in all my recasts per each world.

I’d appreciate any help as this is game-breaking :frowning:

Ah, I see, you cant touch “can be main nav data” checkbox in project settings AT ALL after starting. Doing so will for some reason prevent it from working, even if you have it checked on your recast as well. This is a really dumb annoying bug.

I’ve just found out the solution.

  1. Close your game project
  2. Open your game directory > config
  3. Open defaultengine.ini
  4. Find for bCanBeMainNavData=False
  5. Set it to true

I had the problem in the past few days and I managed to figured it out.

1 Like

I never comment but I wanted to say thank you for posting even after this thread became old. I spent a good few days trying to figure out why my navigation was broken when I built to android and in the process I unchecked main data (which is also a hidden checkbox under a dropdown arrow) so it didn’t work period until turning back on and still having issues on build but now it’s fixed on both ends.

I have had serious frustrations with bugs that shouldn’t be bugs and not seeing help from devs just disappointed me. Probably because they’ve preoccupied themselves on making UE5 WHILE making UE4.27. Hate split development approaches instead of focusing on the one engine version. I had another bug where the engine didn’t save my game instance change, I had to edit the ini again. It really is ridiculous sometimes.

Now navigation just breaks when using Open Level Node.
(This was fixed by setting the recastnavmesh in the LEVEL to “Runtime Generation: Dynamic” while being able to leave the runtime generation in Project Settings to Static)

What’s going on is that there are navmesh values also in your project settings, and those are overwriting the values in your navmesh in your level whenever you restart Unreal.

Go to Edit > Project Settings > Engine > Navigation Mesh

Change the values in the project settings to the ones you want, and they’ll overwrite the values in the navmesh in your level and won’t go back after restart. I’d love an explanation why these values in particular work like this, if anyone knows.